2015 endodontics principles and practice 5th edition

8182019 2015 Endodontics Principles and Practice 5th Edition

httpslidepdfcomreaderfull2015-endodontics-principles-and-practice-5th-edition 140





Endodontics

F I F T H E D I T I O N

PRINCIPLES AND PRACTICE

Mahmoud Torabinejad DMD MSD PhDProfessor and Program Director

Department of Endodontics

School of Dentistry

Loma Linda University

Loma Linda California

Richard E Walton DMD MSProfessor Emeritus


The University of Iowa

College of DentistryIowa City Iowa

Ashraf F Fouad BDS DDS MSDepartment of Endodontics

Prosthodontics and Operative Dentistry

School of Dentistry

University of Maryland

Baltimore Maryland



Printed in China

Last digit is the print number 9 8 7 6 5 4 3 2 1

Executive Content Strategist Kathy Falk Senior Content Development Specialist Brian LoehrPublishing Services Manager Julie EddySenior Project Manager Richard Barber

Design Direction Karen Pauls

3251 Riverport LaneSt Louis Missouri 63043

ENDODONTICS PRINCIPLES AND PRACTICE ISBN 978-1-4557-5410-6Copyright copy 2015 by Saunders an imprint of Elsevier Inc

No part of this publication may be reproduced or transmitted in any form or by any means electronic ormechanical including photocopying recording or any information storage and retrieval system withoutpermission in writing from the publisher Details on how to seek permission further information about thePublisherrsquos permissions policies and our arrangements with organizations such as the Copyright ClearanceCenter and the Copyright Licensing Agency can be found at our website wwwelseviercompermissions

This book and the individual contributions contained in it are protected under copyright by the Publisher(other than as may be noted herein)

Notices

Knowledge and best practice in this field are constantly changing As new research and experiencebroaden our understanding changes in research methods professional practices or medical treatment maybecome necessary

Practitioners and researchers must always rely on their own experience and knowledge in evaluatingand using any information methods compounds or experiments described herein In using suchinformation or methods they should be mindful of their own safety and the safety of others includingparties for whom they have a professional responsibility

With respect to any drug or pharmaceutical products identified readers are advised to check the mostcurrent information provided (i) on procedures featured or (ii) by the manufacturer of each product to beadministered to verify the recommended dose or formula the method and duration of administration andcontraindications It is the responsibility of practitioners relying on their own experience and knowledgeof their patients to make diagnoses to determine dosages and the best treatment for each individualpatient and to take all appropriate safety precautions

To the fullest extent of the law neither the Publisher nor the authors contributors or editors assumeany liability for any injury andor damage to persons or property as a matter of products liabilitynegligence or otherwise or from any use or operation of any methods products instructions or ideascontained in the material herein

Previous editions copyrighted 1989 1996 2002 2009

ISBN 978-1-4557-5410-6



v

Contributors

George Bogen DDSLecturerDepartment of EndodonticsLoma Linda UniversityLoma Linda CaliforniaUniversity of CaliforniaLos Angeles California

Nestor Cohenca DDSTenured ProfessorEndodontics and Pediatric DentistrySchool of DentistryUniversity of WashingtonSeattle Washington

Paul D Eleazer DDSProfessor Chair Program DirectorDepartment of EndodonticsUniversity of Alabama at BirminghamBirmingham Alabama

Ashraf F Fouad BDS DDS MSDepartment of EndodonticsProsthodontics and Operative DentistrySchool of Dentistry

University of MarylandBaltimore Maryland

Charles J Goodacre DDSProfessorRestorative DentistrySchool of DentistryLoma Linda UniversityLoma Linda California

Robert Handysides DDSAssociate Dean for Academic AffairsSchool of DentistryLoma Linda University


Eric J Herbranson DDS MSLecturerDepartment of EndodonticsSchool of DentistryLoma Linda UniversityLoma Linda CaliforniaPractitionerSan Leandro California

Van T Himel DDSProfessor ChairDepartment of EndodonticsLouisiana State UniversityNew Orleans Louisiana

Graham Rex Holland BDS PhDProfessorDepartment of CariologyRestorative Sciences and EndodonticsSchool of DentistryUniversity of MichiganAnn Arbor Michigan

Bradford R Johnson DDS MHPEAssociate Professor Director of Postdoctoral EndodonticsDepartment of EndodonticsUniversity of Illinois at ChicagoChicago Illinois

James D Johnson DDS MSChair Advanced Program DirectorDepartment of EndodonticsSchool of DentistryUniversity of Washington

Seattle Washington

William T Johnson DDS MSRichard D Walton Professor and ChairDepartment of EndodonticsCollege of DentistryThe University of IowaIowa City Iowa

Bruce C Justman DDSClinical Associate ProfessorDepartment of EndodonticsCollege of DentistryThe University of Iowa

Iowa City Iowa

Bekir Karabucak DMD MSAssociate Professor Graduate Program DirectorDepartment of EndodonticsSchool of Dental MedicineUniversity of PennsylvaniaPhiladelphia Pennsylvania



ENDODONTICS

vi

Ilan Rotstein DDSProfessor ChairDepartment of Endodontics Oral and Maxillofacial Surgery

and OrthodonticsOstrow School of DentistryUniversity of Southern CaliforniaLos Angeles California

Mohammad A Sabeti DDS MAAssistant ProfessorDepartment of EndodonticsSchool of DentistryLoma Linda UniversityLoma Linda California

Kent A Sabey DDSProgram DirectorAdvanced Education in EndodonticsDepartment of EndodonticsLouisiana State UniversitySchool of DentistryNew Orleans Louisiana

Shahrokh Shabahang DDS MS PhDAssociate ProfessorDepartment of EndodonticsSchool of DentistryLoma Linda UniversityLoma Linda California

Joseacute F Siqueira Jr DDS MSc PhDProfessor ChairDepartment of Endodontics and Molecular Microbiology

LaboratoryFaculty of DentistryEstaacutecio de Saacute UniversityRio de Janeiro Brazil

Anthony J Smith BSc PhDProfessorOral BiologySchool of DentistryUniversity of BirminghamBirmingham Great Britain

Mahmoud Torabinejad DMD MSD PhDProfessor and Program DirectorDepartment of EndodonticsSchool of Dentistry

Loma Linda UniversityLoma Linda California

Richard E Walton DMD MSProfessor EmeritusDepartment of EndodonticsThe University of IowaCollege of DentistryIowa City Iowa

James C Kulild DDS MSProfessor EmeritusDepartment of EndodonticsUniversity of MissouriSchool of DentistryKansas City Missouri

Harold H Messer BDSc MDSc PhD

Professor EmeritusRestorative DentistrySchool of Dental MedicineUniversity of MelbourneMelbourne Victoria Australia

W Craig Noblett DDSAssistant Clinical ProfessorDivision of EndodonticsDepartment of Preventive and Restorative Dental SciencesSan Francisco School of DentistryUniversity of CaliforniaSan Francisco CaliforniaPrivate Practice

Berkeley California

John M Nusstein DDS MSAssociate Professor ChairDepartment of EndodonticsCollege of DentistryThe Ohio State UniversityColumbus Ohio

Ove A Peters DMD MS PhDProfessor Co-ChairDepartment of EndodonticsUniversity of the PacificArthur A Dugoni School of DentistrySan Francisco California

Al Reader DDS MSProfessor Program DirectorDepartment of EndodonticsCollege of DentistryThe Ohio State UniversityColumbus Ohio

Eric M Rivera DDS MSAssociate Professor Chair and Graduate Program DirectorDepartment of EndodonticsSchool of Dentistry

University of North CarolinaChapel Hill North Carolina

Paul A Rosenberg DDSProfessor Director of Advanced Education ProgramDepartment of EndodonticsNew York UniversityCollege of DentistryNew York New York



viii

Preface

The primary objective of dentists has always been to relievedental pain and prevent tooth loss Despite this effort manyteeth develop caries suffer traumatic injury or are impactedby other diseases and disorders often requiring endodonticcare Endodontics is a discipline of dentistry that deals withthe morphology physiology and pathology of the humandental pulp and periapical tissues as well as the preventionand treatment of diseases and injuries related to these tissuesIts scope is wide and includes diagnosis and treatment of pain

of pulpal andor periapical origin vital pulp therapy regenera-tive endodontic procedures nonsurgical root canal treatmentretreatment of unsuccessful treatment internal bleaching andendodontic surgery Ultimately the primary goal in endodon-tics is to preserve the natural dentition Root canal treatmentis a well-tested procedure that has provided pain relief andhas restored function and esthetics to patients Millions ofpatients expect preservation of their natural dentition if rootcanal treatment is necessary they should be aware that theprocedure is safe and has a high success rate if properlyperformed

As with other dental specialties the practice of endodonticsrequires two inseparable components art and science Theart consists of executing technical procedures during root

canal treatment The science includes the basic and clinicalsciences related to biological and pathological conditions thatguide the art of endodontics through the principles andmethods of evidence-based treatment Evidence-based treat-ment integrates the best clinical evidence with the practitio-nerrsquos clinical expertise and the patientrsquos treatment needs andpreferences A principal objective of our textbook is to incor-porate evidence-based information when available and whenappropriate

Because there are not enough endodontists to manage theendodontic needs of the public general dentists must assistendodontists to preserve natural dentition Their responsibilityis to diagnose pulpal and periapical diseases and to performnoncomplicated root canal treatments In fact most of the

endodontic procedures are performed by generalists Our text-book written specifically for dental students and general den-tists contains the information necessary for those who wouldlike to incorporate endodontics in their practice This includesdiagnosis and treatment planning as well as management ofpulpal and periapical diseases In addition the general dentistmust be able to determine the case complexity and whethershe or he can perform the necessary treatment or if referral isthe better option

Although many advances have been made in endodonticsin the past decade the main objectives of root canal therapycontinue to be the removal of diseased tissue the elimination

of microorganisms and the prevention of recontaminationafter treatment This new edition of Endodontics Principlesand Practice has been systematically organized to simulatethe order of procedures performed in a clinical setting Itcontains information regarding normal structures etiology ofdisease diagnosis and treatment planning local anesthesiaemergency treatment root canal instruments access prepara-tions cleaning and shaping obturation and temporization Inaddition it covers etiology prevention and treatment of acci-

dental procedural errors as well as treatment of inadequateroot canalndashtreated teeth using nonsurgical and surgicalapproaches A chapter is dedicated to the endodontic out-comes that provide guidelines regarding the assessment ofoutcomes of these procedures In this edition wersquove includedinformation on pulp and periapical stem cells regenerativeendodontic procedures novel analyses of endodontic micro-flora the use of cone beam CT in endodontics the interactionof general dentists and endodontists and systemic consider-ations in endodontics Furthermore a chapter discusses singletooth implant

The other distinctive features of the new edition are(1) updated relevant and recent references (2) informationregarding new scientific and technological advances in the

field of endodontics (3) information regarding single toothimplant and (4) a revised contents with new authors Theappendix provides colorized illustrations that depict the sizeshape and location of the pulp space within each tooth Thereis also a website with video clips for selected procedures andan interactive version of the self-assessment questions Thesefeatures provide the reader with a textbook that is concisecurrent and easy to follow in an interactive manner

This textbook is not intended to include all backgroundinformation on the art and science of endodontics At the sametime it is not designed to be a ldquocookbookrdquo or a preclinicallaboratory technique manual We have tried to provide thereader with the basic information to perform root canal treat-ment and to give the reader background knowledge in related

areas This textbook should be used as a building block forunderstanding the etiology and treatment of teeth with pulpaland periapical diseases then the reader can expand her or hisendodontic experiences with more challenging cases Provid-ing the best quality of care is the guiding light for treatmentplanning and performing appropriate treatment

We thank the contributing authors for sharing their materi-als and experiences with our readers and with us Their con-tributions improve the quality of life for millions of patientsWe also express our appreciation to the editorial staff ofElsevier whose collaboration and dedication made thisproject possible and Mohammad Torabinejad for editing and



1

1

The biology of dental pulpand periradicular tissues

Graham Rex Holland Mahmoud Torabinejad

After reading this chapter the student should be able to

1 Describe the development of pulp

2 Describe the process of root development

3 Recognize the anatomic regions of pulp

4 List all cell types in the pulp and describe their

function

5 Describe both fibrous and non-fibrous components of

the extracellular matrix of pulp

6 Describe the blood vessels and lymphatics of pulp

7 List the neural components of pulp and describe their

distribution and function

8 Discuss theories of dentin sensitivity

9 Describe the pathway of efferent nerves from pulp to the

central nervous system

10 Describe the changes in pulp morphology that occur with

age

11 Describe the structure and function of the periradicular

tissues

Development of the Dental Pulp

Anatomic Regions and Their Clinical Importance

Pulp Function

Morphology

Cells of the Dental Pulp

Extracellular Components

Blood Vessels

Innervation

Age Changes in the Dental Pulp and Dentin

Repair and Regeneration

Periradicular Tissues

CHAPTER OUTLINE

LEARNING OBJECTIVES

The dental pulp is the loose connective tissue in thecenter of the tooth The primary function of the pulp isto form and support the dentin that surrounds it and

forms the bulk of the tooth The pulp contains odontoblaststhat not only form dentin but also interact with dental epithe-lium early in tooth development to initiate the formation ofenamel The pulp remains vital throughout life and is able torespond to external stimuli Both dentin and pulp containnociceptive nerve fibers Autonomic nerve fibers occur onlyin the pulp When needed for repair more dentin can be laiddown and new odontoblasts differentiated

The pulp is equipped with all the necessary peripheralcomponents of the immune system and will react to foreign

antigens such as those presented by dental caries Injury andforeign antigens lead to inflammation and pain The goodhealth of the pulp is important to the successful completionof restorative and prosthetic dental procedures In restorativedentistry for example the size and shape of the pulp must beconsidered in determining cavity depth The size and shapeof the pulp depend on the tooth type (eg incisor molar) thedegree of tooth development related to the age of the patientand any restorative procedures that may have been carried outon the tooth When a tooth is injured the stage of developmentthe pulp influences the type of treatment rendered Proceduresroutinely undertaken on a fully developed tooth are not always

practicable for a tooth that is only partially developed andspecial procedures are applied

Because endodontics involves the diagnosis and treatmentof diseases of the pulp and their sequelae a knowledge of thebiology of the pulp is essential for the development of anevidence-based treatment plan This chapter presents an over-view of the biology of the pulp and the periodontium as afundamental component of the evidential base

DEVELOPMENT OF THE DENTAL PULP

Early Development of PulpThe tooth originates as a band of epithelial cells the dentallamina (Fig 11 A) on the surface of the embryonic jawsDowngrowths from this band ultimately form the teeth Thestages of tooth formation are described by the shapes of thesedowngrowths Initially they look like the bud of a formingflower (bud stage Fig 11 B) The bud becomes invaginatedat the cap stage (Fig 11 C ) The invagination deepens andthe bell stage is reached (Fig 11 D) The bell-shaped down-growth is the enamel organ It is ectodermal in origin and willbe responsible for amelogenesis The tissue within the invagi-nation ultimately becomes the dental pulp known as thedental papilla during the early stages of development Before

1-1



ENDODONTICS1

2

have been identified Disorder at this stage can lead to ano-dontia amelogenesis imperfecta odontogenesis imperfectaand related defects A substantial research effort has beenunderway for some years with a long-term goal of using thesemolecules therapeutically in procedures such as apexogenesisand pulpal regeneration

The differentiation of odontoblasts from undifferentiated

ectomesenchymal cells is initiated and controlled by the ecto-dermal cells of the inner dental epithelium of the enamelorgan The ameloblasts synthesize growth factors and signal-ing molecules that pass into the basal lamina of the epitheliumand from there to the preodontoblast The cells beneath theforming odontoblasts remain as undifferentiated stem cellsand retain the potential to differentiate

Once the odontoblast layer has differentiated the basallamina of the inner dental epithelium that contained the sig-naling molecules disappears and the odontoblasts now linkedto each other by tight junctions desmosomal junctions andgap junctions begin to lay down dentin (see Fig 12 C )1

that the cells it contains differentiate The papilla (and thusthe pulp) is derived from cells that have migrated from theneural crest (ectomesenchymal cells) and mingled with cellsof local mesenchymal origin

During the bell stage the inner layer of cells of the enamelorgan differentiate into ameloblasts (Fig 12 A) This is fol-lowed by the outer layer of cells of the dental papilla differ-

entiating into odontoblasts (Fig 12 B) which begin to laydown dentin in the late bell (or crown) stage (Fig 12 C )From this point on the tissue within the invagination is knownas the dental pulp A layer of tissue begins to differentiatearound the enamel organ and dental papilla and forms thedental follicle which later becomes the periodontal attach-ment The combination of the enamel organ dental papilla pulp and dental follicle is the tooth germ

The histodifferentiation and morphodifferentiation of thetooth germ are genetically determined and executed by agroup of growth factors transcription factors and other sig-naling molecules Several of the genes controlling this process

Fig 11 A Earliest stage of tooth development The dental lamina (DL) invaginates from the oral epithelium (OE) B Bud

stage of tooth development Ectomesenchyme (EM) is beginning to condense around the tooth germ C The cap stage of

tooth development The condensed ectomesenchyme within the invagination is the dental papilla (DP) The dental follicle (DF)

is beginning to develop around the tooth germ D Early bell stage The odontoblast layer (OD) and blood vessels (BV) are

visible in the dental pulp (Courtesy Dr H Trowbridge)

OE

A

DL

B

Bud EM

C

DF

DP

D

OD

BV



THE BIOLOGY OF DENTAL PULP AND PERIRADICULAR TISSUES

3

begins at the cusp tip and progresses in a cervical (apical)direction in a regular rhythm at an average of 45 983221mday2 Crown shape is genetically predetermined by the proliferativepattern of the cells of the inner dental epithelium The firstthin layer of dentin formed is called mantle dentin The direc-tion and size of the collagen fibers in mantle dentin togetherwith the mineralization pattern differ from those in the sub-sequently formed circumpulpal dentin Processes from the

odontoblasts remain at least in the inner part of the dentinaltubules A pattern of matrix formation followed by mineral-ization continues throughout dentin deposition Between 10and 50 983221m of the dentin matrix immediately adjacent to theodontoblast layer remains unmineralized at all times and isknown as predentin

As crown formation occurs nerves and blood vessels beginmigrating into the pulp from the future root apex in a coronaldirection Both undergo branching and narrowing toward theodontoblast layer and at a late stage each forms plexusesbeneath the layer with the nerves extending branches into theodontoblast layer and some of the dentinal tubules Dentinformation continues throughout life in an incremental patternmarked by lines in the matrix and changes in direction of the

tubules The rate of deposition slows in adulthood but nevercompletely stops The rate can increase if the odontoblasts arestimulated by toxin molecules penetrating the dentin

Root FormationIn the developing tooth cells of the inner and outer dentalepithelia meet at a point known as the cervical loop Thisdelineates the end of the anatomic crown and the site whereroot formation begins Root formation is initiated by theapical proliferation of the two fused epithelia now known as Hertwigrsquos epithelial root sheath3 The function of the sheathis similar to that of the inner enamel epithelium during crownformation It provides signals for the differentiation of odon-toblasts and thus acts as a template for the root (Fig 13 A)

Cell proliferation in the root sheath is genetically determinedits pattern regulates whether the root will be wide or narrowstraight or curved long or short or single or multiple Mul-tiple roots result when opposing parts of the root sheathproliferate both horizontally and vertically As horizontal seg-ments of Hertwigrsquos epithelial root sheath join to form theldquoepithelial diaphragmrdquo the pattern for multiple root formationis laid down This pattern is readily discernible when thedeveloping root end is viewed microscopically (Fig 13 B)

After the first dentin in the root has formed the basementmembrane beneath Hertwigrsquos sheath breaks up and the inner-most root sheath cells secrete a hyaline material over thenewly formed dentin After mineralization has occurred thisbecomes the hyaline layer of Hopewell-Smith which helps

bind the soon-to-be-formed cementum to dentin Fragmenta-tion of Hertwigrsquos epithelial root sheath occurs shortly after-ward This fragmentation allows cells of the surroundingdental follicle (the future periodontium) to migrate and contactthe newly formed dentin surface where they differentiate intocementoblasts and initiate acellular cementum formation (Fig 14)4 This cementum ultimately serves as an anchor for thedeveloping principal fibers of the periodontal ligament (PDL)In many teeth cell remnants of the root sheath persist in theperiodontium in close proximity to the root after root develop-ment has been completed These are the epithelial cell restsof Malassez5 Normally functionless in the presence of

Once dentin formation has begun the cells of the inner dentalepithelium begin responding to a signal from the odontoblastsand start to deposit enamel This back-and-forth signal controlis an example of epithelial-mesenchymal interaction a keydevelopmental process that has been heavily studied in thetooth germ model Deposition of unmineralized dentin matrix

Fig 12 A At the late cap stage the internal dental epithelium

(IDE) has differentiated into a layer of ameloblasts but has not laid

down enamel The outer layer of the dental papilla (DP) has not yet

differentiated into odontoblasts B Slightly later than in Fig 12 A

the outer cells of the dental papilla are beginning to become

odontoblasts (OD) at the periphery of what now is the dental pulp(DP) The ameloblasts (A) are fully differentiated but no enamel has

formed yet C In the bell stage the odontoblasts (OB) are laying

down dentin (D) but the ameloblasts (A) have laid down little if

any enamel (Courtesy Dr H Trowbridge)

DP

IDE

A

DP AOD

B

OB

A

D

C



ENDODONTICS1

4

before dentin formation The result is direct communicationbetween pulp and the PDL via a channel through the dentinand cementum that carries small blood vessels and perhapsnerves Lateral canals may be single or multiple large orsmall They may occur anywhere along the root but aremost common in the apical third In molars they may join thepulp chamber PDL in the root furcation Lateral canals are

inflammation they can proliferate and may under certain con-ditions give rise to a radicular cyst6

Formation of Lateral Canalsand Apical ForamenLateral Canals Lateral canals (or synonymously accessory canals) are chan-nels of communication between pulp and PDL (Fig 15)They form when a localized area of root sheath is fragmented

Fig 13 A The formation of Hertwigrsquos epithelial root sheath (HERS) from the internal (IDE) and external (EDE) epithelia

B Hertwigrsquos epithelial root sheath (HERS) has extended Both dentin (D) and cementum (C) have been deposited HERS has

changed direction to form the epithelial diaphragm (ED)

IDE

HERS

EDE

C

HERS

ED

D

BA

Fig 14 Developing dentin (D) cementum (C) periodontal

ligament (PDL) and alveolar bone (AB)

C PDL

AB

D

Fig 15 Anatomic regions of the root canal system highlighting

the pulp horn(s) pulp chamber root canal lateral canal and apical

foramen The pulp which is present in the root canal systemcommunicates with the periodontal ligament primarily through the

apical foramen and the lateral canal(s) (Courtesy Orban Collection)

Pulp horn

Pulp chamber

Root canal

Lateral canal

Apical foramen




5

vessels8 It is extensive and supports the high level of cellularactivity in the area The pattern of innervation is similar tothat of the vasculature The neural supply consists of smallunmyelinated sensory and autonomic nerves and largermyelinated sensory nerves Some of the latter terminate asunmyelinated neural structures thought to be nociceptors andmechanoreceptors

ANATOMIC REGIONS AND THEIRCLINICAL IMPORTANCE

The tooth has two principal anatomic divisions root andcrown that join at the cervix (cervical region) The pulp spaceis similarly divided into coronal and radicular regions Ingeneral the shape and the size of the tooth surface reflect theshape and size of the pulp space The coronal pulp is subdi-vided into the pulp horn(s) and pulp chamber (see Fig 15)Pulp horns extend from the chamber into the cuspal regionIn young teeth they are extensive and may be inadvertentlyexposed during routine cavity preparation

The pulp space becomes asymmetrically smaller after root

growth is complete because of the slower production ofdentin There is a pronounced decrease in the height of thepulp horn and a reduction in the overall size of the pulpchamber In molars the apical-occlusal dimension is reducedmore than the mesial-distal dimension Excessive reductionof the size of the pulp space is clinically significant and canlead to difficulties in locating cleaning and shaping the rootcanal system (Fig 16)

The anatomy of the root canal varies not only between toothtypes but also within tooth types Although at least one canalmust be present in each root some roots have multiple canalsof varying sizes Understanding and appreciating all aspectsof root canal anatomy are essential prerequisites to root canaltreatment

Variation in the size and location of the apical forameninfluences the degree to which blood flow to the pulp may becompromised after a traumatic event Young partially devel-oped teeth have a better prognosis for pulp survival than teethwith mature roots (Fig 17)

Posteruptive deposition of cementum in the region of theapical foramen creates a disparity between the radiographicapex and the apical foramen It also creates a funnel-shapedopening to the foramen that is often larger in diameter thanthe intraradicular portion of the foramen The narrowestportion of the canal is referred to as the apical constriction However a constriction is not clinically evident in all teethThe constriction coincides with the cementodentinal junction (CDJ) The level of the CDJ varies from root to root One

study estimated the junction to be located 05 to 075 mmcoronal to the apical opening7 Theoretically that is the pointwhere the pulp terminates and the PDL begins and it wouldbe the ideal point for a procedure aimed at removing the pulpHowever clinically it is not always possible to locate thatpoint Cleaning shaping and obturation of the root canalshould terminate short of the apical foramen and remain con-fined to the canal to avoid unnecessary injury to the periapicaltissues The determination of root length and the establish-ment of a working length are essential steps in root canal preparation Radiographs and electronic apex locators arehelpful in establishing the root length

clinically significant like the apical foramen they represent pathways along which disease may extend from the pulp to periradicular tissues and from the periodontium to the pulp

Apical ForamenThe epithelial root sheath continues to extend until the fullpredetermined length of the root is reached As the epithelialroot sheath extends it encloses more of the dental pulp until

only an apical foramen remains through which pulpal vesselsand nerves pass During root formation the apical foramen isusually located at the end of the anatomic root When toothdevelopment has been completed the apical foramen issmaller and can be found a short distance coronal to the ana-tomic end of the root7 This distance increases later as moreapical cementum is formed

There may be one foramen or multiple foramina at theapex Multiple foramina occur more often in multirootedteeth When more than one foramen is present the largest oneis referred to as the apical foramen and the smaller onesas accessory canals (Together they constitute the apicaldelta) The diameter of the apical foramen in a maturetooth usually ranges between 03 and 06 mm The largest

diameters are found on the distal canal of mandibular molarsand the palatal root of maxillary molars Foramen size isunpredictable however and cannot be accurately determinedclinically

Formation of the PeriodontiumTissues of the periodontium develop from ectomesenchyme-derived tissue (dental follicle) that surrounds the developingtooth After the mantle dentin has formed enamel-like pro-teins are secreted into the space between the basementmembrane and the newly formed collagen by the root sheathcells This area is not mineralized with the mantle dentinbut does mineralize later from the hyaline layer ofHopewell-Smith After mineralization has occurred the root

sheath breaks down This fragmentation allows cells fromthe follicle to proliferate and differentiate into cementoblastswhich lay down cementum over the hyaline layer Bundlesof collagen produced by fibroblasts in the central regionof the follicle (Sharpeyrsquos fibers) are embedded in theforming cementum and will become the principal fibers of thePDL

At the same time cells in the outermost area of the follicledifferentiate into osteoblasts to form the bundle bone that willalso anchor the periodontal fibers Later periodontal fibro-blasts produce more collagen that binds the anchored frag-ments together to form the principal periodontal fibers thatsuspend the tooth in its socket Loose fibrous connectivetissue carrying nerves and blood vessels remains between the

principal fibers Undifferentiated mesenchymal cells (tissue-specific stem cells) are plentiful in the periodontium andpossess the ability to form new cementoblasts osteoblasts orfibroblasts in response to specific stimuli Cementum formedafter the formation of the principal periodontal fibers is cel-lular and plays a lesser role in tooth support As with thedevelopment of the dental pulp these processes are geneti-cally predetermined and executed via signaling moleculesThere is intense research in this area because it promises trulybiologic approaches to periodontal disease

The blood supply to the periodontium is derived fromthe surrounding bone gingiva and branches of the pulpal



ENDODONTICS1

6

Fig 17 Changes in the anatomy of the tooth root and

pulp space A A small crown-to-root ratio thin dentin

walls and divergent shape in the apical third of the canal

are seen B Four years later a longer root greater

crown-to-root ratio smaller pulp space and thickerdentin walls with a convergent shape are seen

BA

Fig 16 A and B Radiographic changes noted in the shape of the pulp chamber over time The posterior bitewing

radiographs were taken 15 years apart The shapes of the root canal systems have been altered as a result of secondary

dentinogenesis and by the deposition of tertiary dentin when deep restorations are present C Secondary dentin (SD) Ground

section at low power D Secondary dentin (SD) at high power

Primary dentin

SD SD

Primary dentin

BA

DC

PULP FUNCTION

The pulp performs five functions some formative and otherssupportive

InductionPulp participates in the initiation and development of dentin9 When dentin is formed it leads to the formation of enamelThese events are interdependent in that enamel epithelium

induces the differentiation of odontoblasts and odontoblastsand dentin induce the formation of enamel Such epithelial-mesenchymal interactions are the core processes of toothformation

FormationOdontoblasts form dentin10 These highly specializedcells participate in dentin formation in three ways (1) bysynthesizing and secreting inorganic matrix (2) by initially




7

NutritionThe pulp supplies nutrients that are essential for dentin forma-tion and for maintaining the integrity of the pulp itself

DefenseIn the mature tooth the odontoblasts form dentin in responseto injury particularly when the original dentin thickness hasbeen reduced by caries attrition trauma or restorative pro-

cedures Dentin can also be formed at sites where its continu-ity has been lost such as a site of pulp exposure Dentinformation occurs in this situation by the induction differentia-tion and migration of new odontoblasts to the exposure site(Fig 19)

Pulp also has the ability to process and identify foreignsubstances such as the toxins produced by bacteria ofdental caries and to elicit an immune response to theirpresence

transporting inorganic components to newly formed matrixand (3) by creating an environment that permits mineralizationof the matrix During early tooth development primary den-tinogenesis is a rapid process After tooth maturation whenelongation of the root is complete dentin formation continuesat a much slower rate and in a less symmetric pattern (second-ary dentinogenesis) Odontoblasts can also form dentin inresponse to injury which may occur in association with caries

trauma or restorative procedures In general this dentin is lessorganized than primary and secondary dentin and mostlylocalized to the site of injury This dentin is referred to as ter-tiary dentin Tertiary dentin has two forms Reactionary ter-tiary dentin is tubular with the tubules continuous with thoseof the original dentin It is formed by the original odontoblasts Reparative dentin is formed by new odontoblasts differenti-ated from stem cells after the original odontoblasts have beenkilled It is largely atubular (Fig 18)

Fig 18 A Reactionary dentin (RCD) at low power B RCD at high power showing change in direction of tubules (arrows)

C Reparative dentin (RPD) at low power D RPD at high power (Courtesy Dr H Trowbridge)

RCD

Primary dentin

RPD

RPD

A B

D

C



ENDODONTICS1

8

Sensation

Nerves in the pulp can respond to stimuli applied directly tothe tissue or through enamel and dentin Physiologic stimulican only result in the sensation of pain The stimulation ofmyelinated sensory nerves in the pulp results in fast sharppain Activation of the unmyelinated pain fibers results in aslower duller pain Pulp sensation through dentin and enamelis usually fast and sharp and is transmitted by Aδ fibers(narrow myelinated fibers)

MORPHOLOGY

Dentin and pulp are actually a single-tissue complex with ahistologic appearance that varies with age and exposure to

external stimuliUnder light microscopy a young fully developed perma-

nent tooth shows certain recognizable aspects of pulpal archi-tecture In its outer (peripheral) regions subjacent to predentinis the odontoblast layer Internal to this layer is a relativelycell-free area (zone of Weil) Internal to the zone of Weil is ahigher concentration of cells (cell-rich zone) (These featuresare limited to the coronal pulp and are sometimes difficult todiscern) In the center is an area containing mostly fibroblastsand major branches of nerves and blood vessels referred to asthe pulp core (Fig 110)

CELLS OF THE DENTAL PULP

OdontoblastsOdontoblasts are the characteristic cells of pulp They form asingle layer at its periphery synthesize the matrix and controlthe mineralization of dentin11 They produce collagen thatbecomes fibrous and three noncollagenous proteins in whichthe collagen fibers are embedded In the coronal part of thepulp space the odontoblasts are numerous (between 45000and 65000mm2) relatively large and columnar in shape Inthe cervical and midportion of the root their numbers arelower and they appear flattened The morphology of the cellreflects its level of activity larger cells have a well-developed

Fig 19 Reparative dentin bridge (DB) formed over a cariously

exposed pulp (Courtesy Dr H Trowbridge)

DB

synthetic apparatus and the capacity to synthesize morematrix During their life cycle they go through functionaltransitional and resting phases all marked by differences incell size and organelle expression12 Odontoblasts can con-tinue at varying levels of activity for a lifetime Some die byplanned cell death (apoptosis) using an autophagic-lysosomalsystem as the volume of the pulp decreases1213 Disease pro-cesses principally dental caries can kill odontoblasts but if

conditions are favorable these cells can be replaced by newodontoblasts that have differentiated from stem cells (Odon-toblasts are end cells and as such do not undergo further celldivision)

The odontoblast consists of two major components the cellbody and the cell processes The cell body lies subjacent tothe unmineralized dentin matrix (predentin) One large cell process extends outward for a variable distance through atubule in the predentin and dentin Other much smaller pro-cesses extend from the cell body and link odontoblasts to eachother and possibly to fibroblasts The cell body is the synthe-sizing portion of the cell and contains a basally locatednucleus and a variety of organelles in the cytoplasm that aretypical of a secreting cell During active dentinogenesis the

endoplasmic reticulum and the Golgi apparatus are promi-nent and there are numerous mitochondria and vesicles(Fig 111)

Cell bodies are joined by a variety of membrane junctionsincluding gap junctions tight junctions and desmosomesEach junction type has specific functions Desmosomal junc-tions mechanically link the cells into a coherent layer Gap junctions allow communication between cells in the layerTight junctions control the permeability of the layer Thesecretory products of the odontoblasts are released throughthe cell membrane at the peripheral end of the cell body andthrough the cell process The cell-to-cell junctions are special-ized areas of the cell membrane Other parts of the cell mem-brane are specialized to be membrane receptors to which

signaling molecules can attach (as ligands) and therebymodify the behavior of the cell

There are many types of membrane receptors The type andnumber of receptors vary greatly between cell types and atdifferent times of the cellrsquos life The odontoblast has severaltypes of receptors on or within its cell membrane Toll-likereceptors (TLR2 and TLR4) when activated by componentsof gram-positive bacteria (lipoteichoic acid) cause the odon-toblasts to release proinflammatory cytokines (Fig 112) Thisindicates that the odontoblasts can act as antigen-recognitioncells when bacterial products penetrate the dentin14 Otherknown receptors (eg TRPV1 capsaicin receptor and TRK-1vanilloid receptor) are thermosensitive and can sense heat- orcold-induced fluid movement in the tubules (Fig 113)1516

Thus the odontoblast has a role in the immune response andmay act as a nociceptor

Stem Cells (Preodontoblasts)Newly differentiated odontoblasts develop after an injury thatresults in the death of existing odontoblasts They developfrom stem cells (also known as undifferentiated mesenchymalcells) which are present throughout the pulp although densestin its core17 Under the influence of signaling moleculesreleased in response to injury and cell death these precursorcells migrate to the site of injury and differentiate into odon-toblasts18 The key signaling molecules in this process are




9

Odontoblast

Lymphaticvessel

Dendritic cell

Macrophage

Plasma cell

Stem cell

A

Fibroblast

Capillary

Nerve

Dentin

Odontoblast

layer

Capillaries

Predentin

B

CFZCRZ

C

Fig 110 A Diagram of the organization of the peripheral pulp B Peripheral pulp at low power C Peripheral pulp showing

cell-free zone (CFZ) and cell-rich zone (CRZ)

members of the bone morphogenetic protein (BMP) familyand transforming growth factor β These (and other) growth

factors are embedded in dentin matrix although their originis unknown

Dental pulpal stem cells (DSPC) can differentiate not onlyinto odontoblasts but also into other cell types such as osteo-blasts adipocytes cardiac muscle cells and even neuronsThese cells promise to be useful therapeutically in the regen-eration of pulp and other tissues (Fig 114)

FibroblastsFibroblasts are the most common cell type in the pulp and areseen in greatest numbers in the coronal pulp They produceand maintain the collagen and ground substance of the pulp

and alter the structure of the pulp in disease As with odonto-blasts the prominence of their cytoplasmic organelles changes

according to their activity The more active the cell the moreprominent the organelles and other components necessary forsynthesis and secretion As do odontoblasts these cellsundergo apoptotic cell death and are replaced when necessaryby the maturation of less differentiated cells

Before immunocytochemistry and DNARNA analysisbecame available simple techniques such as hematoxylin-eosin staining were used to identify cell types However theycould not detect subtle differences between cell types Usingthose methods the majority of cells in loose connectivetissues such as the pulp were designated as ldquofibroblastsrdquoCertainly there are some main fibroblasts that synthesize and






1

produce both type I and type III Pulpal collagen is presentas fibrils that are 50 nm wide and several micrometerslong They form bundles that are irregularly arranged exceptin the periphery where they lie approximately parallel tothe predentin surface The only noncollagenous fibers presentin the pulp are tiny 10 to 15 nm wide beaded fibrils of fibril-lin a large glycoprotein Elastic fibers are absent from thepulp

The proportion of collagen types is constant in the pulpbut with age there is an increase in the overall collagen contentand an increase in the organization of collagen fibers intocollagen bundles Normally the apical portion of pulp con-tains more collagen than the coronal pulp facilitating pulpec-tomy with a barbed broach or endodontic file during rootcanal treatment

Noncollagenous Matrix 22

The collagenous fibers of the pulp are embedded in a histo-logically clear gel made up of glycosaminoglycans and otheradhesion molecules The glycosaminoglycans link to proteinand other saccharides to form proteoglycans a very diversegroup of molecules They are bulky hydrophilic molecules

that with water make up the gel At least six types of adhe-sion molecules have been detected in the pulp matrix One ofthese fibronectin is responsible for cell adhesion to the matrix

CalcificationsPulp stones or denticles (Fig 115) were once classified astrue or false depending on the presence or absence of atubular structure This classification has been challenged anda new nomenclature based on the genesis of the calcificationhas been suggested Pulp stones have also been classifiedaccording to location Three types of pulp stones have beendescribed free stones which are surrounded by pulp tissueattached stones which are continuous with the dentin andembedded stones which are surrounded entirely by tertiary

dentinPulp stones occur in both young and old patients and may

occur in one or several teeth A recent radiographic (bitewing)survey of undergraduate dental students found that 46 ofthem had one or more pulp stones and that 10 of all theteeth contained a pulp stone Pulp stones occur in normalpulps and in chronically inflamed pulps They are not respon-sible for painful symptoms regardless of size

Calcifications may also occur in the form of diffuse orlinear deposits associated with neurovascular bundles in thepulp core This type of calcification is seen most often inaged chronically inflamed or traumatized pulp Dependingon shape size and location pulp calcifications may ormay not be detected on a dental radiograph (Fig 116) Large

pulp stones are clinically significant because they may blockaccess to canals or the root apex during root canal treatment

BLOOD VESSELS

Mature pulp has an extensive and specialized vascular patternthat reflects its unique environment23 The vessel network hasbeen examined using a variety of techniques including Indiaink perfusion transmission electron microscopy scanningelectron microscopy and microradiography

of numbers (estimated at 8 of the pulp) and position are themost prominent in the pulp Special stains are needed to rec-

ognize them histologicallyMacrophages in a resting form (histiocytes) and some

T lymphocytes are also found in the normal pulp20

EXTRACELLULAR COMPONENTS21

FibersThe predominant collagen in dentin is type I both type I andtype III collagens are found within pulp in a ratio of approxi-mately 55 45 Odontoblasts produce only type I collagenfor incorporation into the dentin matrix whereas fibroblasts

Fig 114 Stem cells from exfoliated deciduous teeth (SHED)

were placed on a scaffold in a tooth slice from which the pulp had

been removed The slice was then placed subcutaneously in a

mouse and left for 32 days A The pulp and dentin were examined

a month after placement The stem cells differentiate into functionalodontoblasts and endothelial cells (hematoxylin-eosin) B Once the

stem cells differentiated into functional odontoblasts they

generated tubular dentin This is demonstrated by injecting

tetracycline intraperitoneally every 5 days and observing a section

of the slice in a confocal microscope The bright lines indicate

areas where the tetracycline has been incorporated into the dentin

(From Sakai VT Cordeiro MM Dong Z et al Advances in dental

research tooth slicescaffold model of dental pulp tissue

engineering Thousand Oaks Calif Jun 15 2011 Sage Publishing)

B

A



ENDODONTICS1

12

as one or two larger vessels through the apical foramen (Figs 120 and 121) The lymphatic vessel walls are composed ofan endothelium rich in organelles and granules There are

discontinuities in the walls of these vessels and in their base-ment membranes This porosity permits the passage of inter-stitial tissue fluid and when necessary lymphocytes into thenegative-pressure lymph vessel The lymphatics assist in theremoval of inflammatory exudates and transudates and cel-lular debris After exiting from the pulp some vessels joinsimilar vessels from the PDL and drain into regional lymphglands (submental submandibular or cervical) before empty-ing into the subclavian and internal jugular veins An under-standing of lymphatic drainage assists in the diagnosis ofinfection of endodontic origin

Vascular Physiology The dental pulp at least when young is a highly vascular

tissue Capillary blood flow in the coronal region is almosttwice that of the radicular region Blood supply is regulatedlargely by the precapillary sphincters and their sympatheticinnervation28 Other local factors and peptides released fromsensory nerves also affect the vessels most prominently duringinflammation

As in other tissues the volume of the vascular bed is muchgreater than the volume of blood that is normally passingthrough it Only part of the vascular bed is perfused at anyone time This capacity allows for sizable local increases inblood flow in response to injury

The factors that determine what passes in and out betweenthe blood and the tissue include concentration gradients

Afferent Blood Vessels (Arterioles)The largest vessels to enter the apical foramen are arteriolesthat are branches of the inferior alveolar artery the superior

posterior alveolar artery or the infraorbital arteryOnce inside the radicular pulp the arterioles travel toward

the crown They narrow then branch extensively and lose theirmuscle sheath before forming a capillary bed (Fig 117) Themuscle fibers before the capillary bed form the ldquoprecapillarysphinctersrdquo which control blood flow and pressure The mostextensive capillary branching occurs in the subodontoblasticlayer of the coronal pulp where the vessels form a denseplexus (Fig 118)24 The loops of some of these capillariesextend between odontoblasts22 The exchange of nutrients andwaste products takes place in the capillaries (Fig 119)25 There is an extensive shunting system composed of arteriove-nous and venovenous anastomoses these shunts becomeactive after pulp injury and during repair

Efferent Blood VesselsVenules constitute the efferent (exit) side of the pulpal circula-tion and are slightly larger than the corresponding arteriolesVenules are formed from the junction of venous capillariesand enlarge as more capillary branches unite with them Theyrun with the arterioles and exit at the apical foramen to drainposteriorly into the maxillary vein through the pterygoidplexus or anteriorly into the facial vein

Lymphatics2627

Lymphatic vessels arise as small blind thin-walled vessels inthe periphery of the pulp They pass through the pulp to exit

Fig 115 A Multiple stones in coronal pulp B Stones occluding a pulp chamber C Lamellated pulp stone (Courtesy Dr H

Trowbridge)

A

B

C




1

Fig 116 Multiple pulp stones (arrows) in the pulp chamber and

root canals of the anterior (A) and posterior (B) teeth of a young

patient

A

B

Fig 117 Schematic of the pulpal vasculature Smooth

muscle cells that surround vessels and precapillary sphincters

selectively control blood flow Arteriovenous shunts bypass

capillary beds

Arteriole

Metarteriole

Capillaries

Small venule

VenuleLymphvessel

Precapillary sphincter

Arteriovenousshunt

Vascular smooth

muscle cells

Vascular Changes During Inflammation30

When the dental pulp is injured it responds in the same wayas other connective tissues with a two-phase immune responseThe initial immune response is nonspecific but rapid occur-ring in minutes or hours The second response is specificand includes the production of specific antibodies Beforethe detailed nature of the immune response was known thephenomenon associated with the response to tissue injury

including redness pain heat and swelling was known asinflammation Although much more is now known about theresponse to injury at the cellular level these ldquocardinal signsrdquoremain important Except for pain they are all vascular inorigin Heat and redness are results of increased blood flowand swelling results from increased formation of interstitialtissue fluid because of increased permeability of the capillar-ies In other tissues such as skin (in which inflammation wasfirst described) the increased production of tissue fluid resultsin swelling Because the dental pulp is within a rigid non-compliant chamber it cannot swell and the increased inter-stitial fluid formation results in an increase in tissue fluidpressure

At one time it was thought that this rise in interstitial fluid

pressure would spread rapidly and strangle vessels enteringthe root canal at the apical foramen Closer study has revealedthat this is not the case Elevations in tissue fluid pressureremain localized to the injured area A short distance from theinjury tissue fluid pressure is maintained within normal limitsAs interstitial fluid pressure rises the intraluminal (inside)pressure of the local capillaries increases to balance this sothat the vessels remain patent During the response to injurythe gradients by which nutrients and wastes leave and enterthe capillaries change to allow greater exchange At the sametime these changes occur in the capillaries lymphatic vesselsbecome more heavily employed removing excess tissue fluidand debris In addition anastomoses in the microvascular bedallow blood to be shunted around an area of injury so that the

oxygenation and nutrition of nearby uninjured tissue are notcompromised If the cause of the injury is removed theseprocesses gradually return the vasculature to normal andrepair or regeneration can take place If the injury persists andincreases in size this tissue necroses This necrosis can remainlocalized as a pulpal abscess although it more often spreadsthroughout the pulp The necrosis extends as the toxins fromthe carious lesion diffuse through the tissue

osmosis and hydraulic pressure Concentration gradients varyalong the capillary bed as oxygen for example diffuses outinto the depleted tissue and carbon dioxide (CO2) enters fromhigh to low concentration The hydraulic pressure in thepulpal capillaries falls from 35 mm Hg at the arteriolar endto 19 mm Hg at the venular end Outside the vessel the inter-stitial fluid pressure varies but a normal figure would be6 mm Hg29



ENDODONTICS1

14Fig 119 A Subodontoblastic capillary plexus B Capillary within the odontoblast layer C Branching capillaries in

subodontoblastic plexus D Arteriole (A) and venules (V) in the peripheral pulp (Courtesy Dr H Trowbridge)

V

A

BA

DC

Fig 118 The dense capillary bed in the subodontoblastic region

is shown by resin cast preparation and scanning electron

microscopy (Courtesy Dr C Kockapan)

The vascular changes seen in inflammation are largelymediated by local nerves The sympathetic fibers through theprecapillary sphincters can alter the pressure flow and distri-bution of blood Sensory nerve fibers release a number ofneuropeptides most prominently calcitonin genendashrelatedpeptide (CGRP) and substance P (These names are of historicorigin and unrelated to the function of these molecules in thissetting) The release of these neuropeptides comes about

through axon reflexes whereby one branch of a sensory nervestimulated by the injury causes the release of the peptides byanother branch This mechanism in which excitation ofsensory elements results in increased blood flow and increasedcapillary permeability is known as neurogenic inflammation

INNERVATION

The second and third divisions of the trigeminal nerve (V2 andV3) provide the principal sensory innervation to the pulp ofmaxillary and mandibular teeth respectively Mandibular pre-molars can also receive sensory branches from the mylohyoidnerve of V3 which is principally a motor nerve Branches

from this nerve reach the teeth via small foramina on thelingual aspect of the mandible Mandibular molars occasion-ally receive sensory innervation from the second and thirdcervical spinal nerves (C2 and C3) This can create difficultiesin anesthetizing these teeth with an inferior dental block injec-tion only




1

parasympathetic innervation of the pulp This is not unusualAll tissues have an autonomic innervation but not always

from both divisions

Neuroanatomy Pulpal and Dentinal Nerves Sensory nerves supplying the dental pulp contain both myelin-ated and unmyelinated axons (Fig 122) The myelinatedaxons are almost all narrow slow-conducting Aδ axons (1 to6 983221m in diameter) associated with nociception A small per-centage of the myelinated axons (1 to 5) are faster-conducting Aβ axons (6 to 12 983221m in diameter) In othertissues these larger fibers can be proprioceptive or mechano-receptive Their role in the pulp is uncertain but it isnow known from other tissues that in inflammation theseAβ axons can be recruited to the pain system Before they

terminate all the myelinated axons lose their myelin sheathand terminate as small unmyelinated branches either belowthe odontoblasts around the odontoblasts or alongside theodontoblast process in the dentinal tubule (Fig 123)31 Beneath the odontoblast layer these terminating fibers formthe subodontoblastic plexus of Raschkow (Fig 124)

The nerves that enter the dentinal tubules do not synapsewith the process but remain in close proximity with it for partof its length Approximately 27 of the tubules in the area ofthe pulp horn of a young mature tooth contain an intratubularnerve These nerves occur less often in the middle (11) andcervical portions (8) of the crown and not at all in the root32

Cell bodies of trigeminal nerves are located in the trigemi-nal ganglion Dendrites from these nerves synapse with

neurons in the trigeminal sensory nucleus in the brainstemSecond-order neurons here travel to specific nuclei in thethalamus Third-order neurons and their branches reach thesensory cortex and a number of other higher centers

Pulp also receives sympathetic (motor) innervation from T1and to some extent C8 and T2 via the superior cervical gan-glion These nerves enter the pulp space alongside the mainpulp blood vessels and are distributed with them Theymaintain the vasomotor tone in the precapillary sphincterswhich control the pressure and distribution of bloodThe presence of parasympathetic nerve fibers in the pulp hasbeen controversial The current consensus is that there is no

Fig 120 Distribution of lymphatics Scanning electron

micrograph of secondary and back-scattered electrons after

specific immune staining (From Matsumoto Y Zhang B Kato S

Microsc Res Tech 5650 2002)

Fig 121 Transmission electron micrograph of a lymphatic vessel

(L) in the peripheral pulp (From Matsumoto Y Zhang B Kato S

Lymphatic networks in the periodontal tissue and dental pulp as

revealed by histochemical study Microsc Res Tech 5650 2002)

L

Fig 122 Pulp nerves in region of the pulp core A group of

unmyelinated (UNA) and myelinated (MNA) nerve axons are shown

in cross section A Schwann cell (SC) associated with one of the

myelinated axons is evident Nerves are surrounded by collagen

fibers (CO)



ENDODONTICS1

16

some time after tooth eruption As a result there are signifi-cant variations in the responses of partially developed teeth topulp vitality tests This undermines the value of stimulatorytests for determining pulp status in young patients particu-larly after trauma

The number of pulpal nerves diminishes with age Thesignificance of this reduction in terms of responses to vitalitytesting is undetermined

Pathways of Transmission from Pulp toCentral Nervous SystemMechanical thermal and chemical stimuli initiate an impulsethat travels along the pulpal axons in the maxillary (V2) ormandibular (V3) branches of the trigeminal nerve to the tri-geminal (gasserian) ganglion which contains the cell body ofthe neuron Dendrites from the ganglion then pass centrallyand synapse with second-order neurons in the trigeminalnuclear complex located at the base of the medulla and theupper end of the spinal cord Most of the activity that origi-nates in the dental pulp is conducted along axons that synapsewith neurons in the spinal portion of the complex mostnotably the subnucleus caudalis

Many peripheral axons from different sites synapse on asingle secondary neuron a phenomenon known as conver-gence Activity in a single synapse does not result in excitationof the second-order neuron Activity in many synapses mustsummate to reach the threshold of the second-order neuronThe activation of the second-order neuron is also affected byfibers from the midbrain that belong to the endogenous opioidsystem These when active reduce the activity of the second-order neurons Thus noxious input is modulated explainingwhy the pain experience is not always closely related to thedegree of peripheral noxious stimulation Axons from thesecond-order neurons cross the midline and synapse in tha-lamic nuclei From here third-order neurons pass informationto a variety of higher centers the sensory cortex being only

one of them The distribution of noxious input centrally andthe presence of a pain-modulating system descending fromhigher centers provide the broad framework for understandingand controlling pain As a result of persistent noxious inputthe properties of second-order neurons can change Thesechanges can be used to explain some of the complexities ofdiagnosing and treating pain as described in other sections ofthis text

Theories of Dentin Hypersensitivity Pain elicited by scraping or cutting of dentin or by the applica-tion of cold or hypertonic solutions to exposed dentin givesthe impression that there may be a nerve pathway from thecentral nervous system to the dentinoenamel junction (DEJ)

However no direct pathway is present The application ofpain-producing substances such as histamine acetylcholineor potassium chloride to exposed dentin surface fails toproduce pain Eliciting pain from exposed dentin by heat orcold is not blocked by local anesthetics At one time it wasthought that dentin sensitivity was due to sensory nerveswithin the dentinal tubules

Currently two explanations for peripheral dentin sensitivityhave broad acceptance (Fig 125) One is that stimuli that areeffective in eliciting pain from dentin cause fluid flow throughthe dentinal tubules33 This disturbance results in the activa-tion of nociceptors in the inner dentin and peripheral pulp

Their incidence is higher in predentin than in mineralizeddentin

Developmental Aspects of Pulp InnervationThe types and relative number of nerves depend on the stateof tooth maturity Myelinated nerves enter the pulp at aboutthe same time as unmyelinated nerves but in most instancesdo not form the subodontoblastic plexus of Raschkow until

Fig 123 A Silver-stained section of pulp in a young human

molar demonstrates arborization of nerves in the subodontoblastic

region and a nerve (arrow) passing between odontoblasts into the

predentin area B Transmission electron micrograph demonstrates

an unmyelinated nerve axon (arrow) alongside the odontoblast

process in the dentin tubule at the level of the predentin

( A Courtesy Dr S Bernick)

A

B

Fig 124 Raschkowrsquos subodontoblastic plexus (arrows) stained

with silver




1

dentin This occurs in two forms (1) tertiary response dentin

which is formed by the original odontoblasts and is tubular instructure and (2) tertiary reparative dentin which is formedafter the original odontoblasts have been killed and is createdby odontoblasts differentiated from stem cells The type ofdentin laid down is determined by the intensity of thestimulus

Stem cells can be isolated from exfoliated deciduous teeth(known as ldquoSHEDrdquo cells) and have been shown in an animalmodel to form new dentin and pulp in slices of tooth fromwhich the pulp has been removed (Fig 114)35 This leads tothe happy prospect that the pulp may be regenerated in pulp-less teeth

PERIRADICULAR TISSUES

The periodontium the tissue surrounding and investing theroot of the tooth consists of the cementum PDL and alveolarbone (Fig 126) These tissues originate from the dentalfollicle that surrounds the enamel organ their formation isinitiated when root development begins36 After the toothhas erupted the cervical portion of the tooth is in contactwith the epithelium of the gingiva which in combinationwith reduced dental epithelium on the enamel forms the den-togingival junction When intact this junction protects theunderlying periodontium from potential irritants in the oralcavity The pulp and the periodontium form a continuumat sites along the root where blood vessels enter and exit the

pulp at the apical foramen and lateral and accessory canals(Fig 127)

CementumCementum is a bonelike tissue that covers the root and pro-vides attachment for the principal periodontal fibers Theseveral types of cementum that have been identified are asfollows

1 Primary acellular intrinsic fiber cementum This is thefirst cementum formed and it is present before principalperiodontal fibers are fully formed It extends from thecervical margin to the cervical third of the tooth in some

Several observations support this ldquohydrodynamic hypothesisrdquo

In experiments on extracted teeth it has been shown that hotcold and osmotic stimuli cause fluid flow through dentin Inhuman subjects the success of solutions in inducing pain isrelated to the osmotic pressure of the solution Exposed dentinthat is sensitive in patients has patent dentinal tubules34

In exposed dentin that is not sensitive the dentinal tubulesare occluded Substances and techniques that occlude dentinaltubules in sensitive dentin eliminate or reduce the sensitivityA second explanation is that some substances can diffusethrough the dentin and act directly on pulpal nerves Evidencefor this largely comes from animal experiments which showthat the activation of pulpal nerves is sometimes related to thechemical composition of a stimulating solution rather than itsosmotic pressure These are not mutually exclusive hypothe-

ses both may apply and both should be addressed in treatingsensitive dentin

AGE CHANGES IN THE DENTAL PULP AND DENTIN

Secondary dentin is laid down throughout life As a resultboth the pulp chamber and root canals become smaller some-times to the point where they are no longer visible on radio-graphs As age increases more peritubular dentin is laiddown often completely occluding the dentinal tubules in theperiphery (sclerotic dentin) As a result of these processes thepermeability of the dentin is reduced The pulp tissue itself

becomes less cellular and less vascular and contains fewernerve fibers Between the ages of 20 and 70 cell densitydecreases by approximately 50 This reduction affects allcells from the highly differentiated odontoblast to the undif-ferentiated stem cell

REPAIR AND REGENERATION

The dental pulp can respond positively to external irritantsincluding the toxins released during dental caries Inflamma-tion is part of the response that leads to the formation of new

Fig 125 Schematic drawing of theoretic

mechanisms of dentin sensitivity A Classic theory

(direct stimulation of nerve fibers in the dentin)

B Odontoblasts as a mediator between the stimuli

and the nerve fibers C Fluid movement as proposed

in hydrodynamic theory (Modified from Torneck CD

Dentin-pulp complex In Ten Cate AR editor Oral

histology ed 4 St Louis 1994 Mosby)

A B C



ENDODONTICS1

18

teeth and around the entire root in others (incisors andcuspids) It is more mineralized on the surface than nearthe dentin and contains collagen produced initially bycementoblasts and later by fibroblasts

2 Primary acellular extrinsic fiber cementum This iscementum that continues to be formed about the primaryperiodontal fibers after they have been incorporated intoprimary acellular intrinsic fiber cementum

3 Secondary cellular intrinsic fiber cementum Thiscementum is bonelike in appearance and only plays aminor role in fiber attachment It occurs most often inthe apical part of the root of premolars and molars

4 Secondary cellular mixed fiber cementum This is anadaptive type of cellular cementum that incorporatesperiodontal fibers as they continue to develop It is vari-able in its distribution and extent and can be recognizedby the inclusion of cementocytes its laminated appear-ance and the presence of cementoid on its surface

5 Acellular afibrillar cementum This is the cementumsometimes seen overlapping enamel which plays norole in fiber attachment

Cementum is similar to bone but harder and thus resists

resorption during tooth movement The junction between thecementum and the dentin (CDJ) that forms the apical constric-tion is ill defined and not uniform throughout its circumfer-ence Biologic principles suggest that the most appropriatepoint to end a root canal preparation is at the junction of thepulp and periodontium which occurs at the apical constric-tion Although many practitioners debate the probabilitiesand practicalities of achieving this goal most agree that it isessential to measure canal length accurately and to restrictall procedures to a canal length that estimates this point asclosely as possible

Although dentin is harder than bone and resorbs moreslowly it does resorb in periapical inflammatory lesions oftenresulting in loss of the apical constriction Occasionally more

rapid resorption of unknown cause is seen (idiopathic resorp-tion) but this is often self-limiting

Cementoenamel JunctionThe junction of cementum and enamel at the cervix of thetooth varies in its arrangement even around a single toothSometimes cementum overlies enamel and vice versa Whenthere is a gap between the cementum and the enamel theexposed dentin may be sensitive

Periodontal LigamentAs is dental pulp the periodontal ligament is a specializedconnective tissue36 Its function relates in part to the presenceof specially arranged bundles of collagen fibers that support

the tooth in the socket and absorb the forces of occlusionpreventing them from being transmitted to the surroundingbone The PDL space is small varying from an average of021 mm in young teeth to 015 mm in older teeth The uni-formity of its width (as seen in a radiograph) is one of thecriteria used to determine its health

Lining the periodontal space are cementoblasts and osteo-blasts Interwoven between the principal periodontal fibers isa loose connective tissue that contains fibroblasts stemcells macrophages osteoclasts blood vessels nerves andlymphatics Epithelial cell rests of Malassez are also present(Fig 128) As already noted these cells are of no known

Fig 126 Peripheral radicular dentin ( H hyaline layer) cementum

(C) periodontal ligament (PDL) and alveolar bone (AB)

AB

PDL

C

H

Fig 127 Apical region of maxillary incisor showing apical

foramen t Transitional tissue between periodontal ligament and

pulp o odontoblasts bv blood vessel




1

sympathetic fibers induces constriction of the vessels As inthe pulp there is no convincing evidence that a parasympa-thetic nerve supply exists

Sensory nerves that supply the periodontium arise from thesecond and third divisions of the trigeminal nerve (V2 and V3)They are mixed nerves of large and small diameter Unmyelin-ated sensory fibers terminate as nociceptive free endingsLarge fibers are mechanoreceptors that terminate in specialendings throughout the ligament but are in greatest concentra-

tion in the apical third of the periodontal space These arehighly sensitive recording pressures in the ligament associ-ated with tooth movement They allow patients to identifyteeth with acute periodontitis with some precision

Alveolar BoneThe bone of the jaws that supports the teeth is referred to asthe alveolar process Bone that lines the socket and intowhich the principal periodontal fibers are anchored is referredto as the alveolar bone proper (bundle bone cribriform plate)Alveolar bone is perforated to accommodate vessels nervesand investing connective tissues that pass from the cancellousportion of the alveolar process to the periodontal spaceDespite these perforations alveolar bone proper is denser than

the surrounding cancellous bone and has a distinct opaqueappearance when seen in periapical radiographs On the radio-graph alveolar bone proper is referred to as lamina dura (Fig 129) Its continuity is equated with periodontal health and itsperforation with disease Radiographic changes associatedwith periradicular inflammatory disease usually follow ratherthan accompany the disease Significant bone loss is neces-sary before a radiographic image is seen

Alveolar bone proper is principally lamellar and continu-ally adapts to the stress of tooth movements Because pres-sures are not constant bone is constantly remodeling (byresorption and apposition)

significance in the healthy periodontium but during inflam-matory states they can proliferate and give rise to cystformation

The vasculature of the periodontium is extensive andcomplex Arterioles that supply the PDL arise from the supe-rior and inferior alveolar branches of the maxillary artery inthe cancellous bone These arterioles pass through smallopenings in the alveolar bone of the socket at times accom-panied by nerves and extend upward and downward through-out the periodontal space They are more prevalent in posterior

than anterior teeth Other vessels arise from the gingiva orfrom dental vessels that supply the pulp These latter vesselsbranch and extend upward into the periodontal space beforethe pulpal vessels pass through the apical foramen The degreeof collateral blood supply to the PDL and the depth of its cellresources impart an excellent potential for its repair subse-quent to injury a potential that is retained for life in theabsence of systemic or prolonged local disease

The periodontium receives both autonomic and sensoryinnervation Autonomic nerves are sympathetics arising fromthe superior cervical ganglion and terminating in the smoothmuscle of the periodontal arterioles Activation of the

Fig 128 A Epithelial rest of Malassez (ERM) in periodontal

ligament (PDL) B Transmission electron micrograph of epithelial

rests (From Cerri PS Katchburian E J Periodont Res 403652005)

PDL

ERM

A

B

Fig 129 Mandibular anterior teeth with normal uniform

periodontal ligament (PDL) space and identifiable lamina dura

(arrows) This usually but not always indicates the absence ofperiradicular inflammation



ENDODONTICS1

20

REFERENCES

1 Koling A Freeze fracture electron microscopy of

simultaneous odontoblast exocytosis and endocytosis

in human permanent teeth Arch Oral Biol 32153

1987

2 Kawasaki K Tanaka S Ishikawa T On the daily

incremental lines in human dentine Arch Oral Biol

24939 1980

3 Luan X Ito Y Diekwisch TGH Evolution and

development of Hertwigrsquos epithelial root sheath Dev

Dyn 581167 20064 Hamamoto Y Nakajima T Ozawa H et al

Production of amelogenin by enamel epithelium of

Hertwigrsquos root sheath Oral Surg Oral Med Oral

Path Oral Radiol Endod 81703 1996

5 Cerri PS Katchburian E Apoptosis in the epithelial

cells of the rests of Malassez of the periodontium of

rat molars J Periodontal Res 40365 20056 Ten Cate AR The epithelial cell rests of Malassez

and genesis of the dental cyst Oral Surg Oral Med

Oral Pathol 34956 1972

7 Kuttler Y Microscopic investigation of root apices

J Am Dent Assoc 50544 1955

8 Saunders RL X-ray microscopy of the periodontal

and dental pulp vessels in the monkey and in man

Oral Surg Oral Med Oral Pathol 22503 1966

9 Lisi S Peterkova R Peterka M et al Tooth

morphogenesis and pattern of odontoblast

differentiation Connect Tissue Res 44(suppl 1)167

200310 Lesot H Lisi S Peterkova R et al Epigenetic

signals during odontoblast differentiation Adv Dent

Res 158 2001

11 Sasaki T Garant PR Structure and organization of

odontoblasts Anat Rec 245235 1996

12 Couve E Ultrastructural changes during the life

cycle of human odontoblasts Arch Oral Biol

31643 1986

13 Franquin JC Remusat M Abou Hashieh I et al

Immunocytochemical detection of apoptosis in

human odontoblasts Eur J Oral Sci 106(suppl

1)384 1998

14 Veerayutthwilai O Byers MR Pham T-T T

et al Differential regulation of immune responses

by odontoblasts Oral Microbiol Immunol 225

2007

15 Magloire H Maurin JC Couble ML et al Dental

pain and odontoblasts facts and hypotheses J

Orofac Pain 24335 2010

16 Sole-Magdalena A Revuelta EG Menenez-Diaz Iet al Human odontoblasts express transient receptor

protein and acid-sensing ion channel mechanosensor

proteins Microsc Res Tech 74457 2011

17 Shi S Bartold PM Miura M et al The efficacy of

mesenchymal stem cells to regenerate and repair

dental structures Orthod Craniofac Res 8191

200518 Smith A Vitality of the dentin-pulp complex in

health and disease growth factors as key mediators

J Dent Ed 67678 2003

19 Jontell M Bergenholtz G Accessory cells in the

immune defense of the dental pulp Proc Finn Dent

Soc 88345 1992

20 Zhang J Kawashima N Suda H et al The existence

of CD11c sentinel and F480 interstitial dendritic

cells in dental pulp and their dynamics and

functional properties Int Immunol 181375 2006

21 Butler WT Ritchie HH Bronckers AL Extracellular

matrix proteins of dentine Ciba Found Symp 205107 1997

22 Linde A Dentin matrix proteins composition and

possible functions in calcification Anat Rec

224154 1989

23 Kramer IRH The vascular architecture of the

human dental pulp Arch Oral Biol 2177 1960

24 Koling A Rask-Andersen H The blood capillaries

in the subodontoblastic region of the human dental

pulp as demonstrated by freeze-fracturing Acta

Odont Scand 41333 1983

25 Iijima T Zhang J-Q Three-dimensional

wall structure and the innervation of dental

pulp blood vessels Microsc Res Tech 5632

2002

26 Marchetti C Poggi P Calligaro A et al Lymphatic

vessels in the healthy human dental pulp Acta Anat

(Basel) 140329 1991

27 Matsumoto Y Zhang B Kato S Lymphatic

networks in the periodontal tissue and dental pulp as

revealed by histochemical study Microsc Res Tech 5650 2002

28 Haug SR Heyeraas KJ Modulation of dental

inflammation by the sympathetic nervous system J

Dent Res 85488-495 2006

29 Heyeraas KJ Berggreen E Interstitial fluid pressure

in normal and inflamed pulp Crit Rev Oral Biol

Med 10328 199930 Kim S Neurovascular interactions in the dental pulp

in health and inflammation J Endod 1648-53

1990

31 Arwill T Edwall L Lilja J et al Ultrastructure of

nerves in the dentinal-pulp border zone after sensory

and autonomic nerve transection in the cat ActaOdont Scand 31273 1973

32 Lilja T Innervation of different parts of predentin

and dentin in young human premolars Acta Odont

Scand 37339 1979

33 Brannstrom M Astrom A The hydrodynamics of

the dentine its possible relationship to dentinal pain Int Dent J 22219 1972

34 Holland GR Morphological features of dentine and

pulp related to dentine sensitivity Arch Oral Biol

39(suppl 1)3S-11S 1994

35 Sakai VT Zhang Z Dong Z et al SHED

differentiate into functional odontoblasts and

epithelium J Dent Res 89791 2010

36 Cho MI Garant PR Development and general

structure of the periodontium Periodontology 2000

249 2000



2


1 Describe pulp protection and pulp therapy

2 Understand the special physiologic and structural

characteristics of the pulp-dentin complex and how they

affect the pulpal response to injury

3 Describe the reparative mechanisms of the pulp

including immune responses and tertiary dentin

formation

4 Describe the effects of dental procedures and materials

on the pulp

5 Appreciate the significance of microleakage and smear

layer on pulp response

6 Describe the indications and procedures for vital pulp

therapy

7 Discuss the effects of pulpal injury in teeth with

developing roots

8 Describe diagnosis and case assessment of immature

teeth with pulp injury

9 Describe the techniques for vital pulp

therapy (apexogenesis) and root-end closure

(apexification)

10 Describe the prognosis for vital pulp therapy and

root-end closure

11 Describe the technique for pulp revascularization and the

goals of regenerative endodontic therapy

12 Recognize the potential of tissue engineering techniques

in regenerating pulpal tissue

13 Consider restoration of the treated immature tooth

Definitions

Iatrogenic Effects on the Dental Pulp

Protecting the Pulp from the Effects of Materials

Vital Pulp Therapies

The Open Apex

2 Protecting the pulp

and promoting

tooth maturationAshraf F Fouad Anthony J Smith

CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS

Pulp ProtectionDental caries represents one of the principal challenges to thehealth of the dental pulp although its treatment may wellexacerbate the challenge Cavity preparation and associatedprocedures the toxicity of restorative materials and signifi-cantly the continuing challenge from leakage of bacteria andtheir products at the margins of restorations can contributefurther damage to that caused by the original caries This maytip the balance from a reversible to an irreversible pulpitis it

also highlights the importance of a holistic approach to man-agement of dental caries which aims to restore the functionalintegrity of the tooth while preserving its vitality and protectthe pulp from further damage

A fundamental consideration in pulp protection is the rec-ognition that infection is a key driver of inflammation whichoften determines the outcomes for pulp survival Thus thepulp always is likely to be inflamed when bacteria from dentalcaries are present and their control should be a significantfeature of any treatment planning Even in teeth with whitespot lesions and for which restorative procedures are not indi-cated pulpal inflammation is frequently present (Fig 21)1

When treatment plans are designed for patients who haveseveral teeth with carious lesions especially when lesions areextensive a ldquotriagerdquo approach is preferable In this approachactive caries is removed and good temporary restorations areplaced at an early stage allowing the pulp the maximumopportunity for recovery

Vital Pulp Therapy Maintenance of pulp vitality should always be the goal intreatment planning and considerable interest is developing inthe concept of regenerative endodontics for complete or

partial pulp tissue regeneration With mechanical exposure ofthe dental pulp by trauma or during cavity preparation thepulp may be protected and its vitality maintained by immedi-ately covering it (pulp capping) and placing a restorationthereby avoiding root canal treatment If the exposure is largeor seriously contaminated it may be possible to remove themore superficial diseased part of the pulp (pulpotomy) capthe remaining pulp and place a restoration This approachprobably has the best prognosis in incompletely formed teeth(especially primary teeth) when the root has not yet reachedits full length (apexogenesis) however it can also be consid-ered for fully formed and permanent teeth with reversible



ENDODONTICS11

178

Fig 116 Preoperative periapical radiograph (A) and clinical photograph (B) of a complicated crown fracture of the maxillary

left central incisor C and D Upon completion of the endodontic therapy a fiber post was placed followed by the coronal

restoration The results are shown in a postoperative clinical photograph (E) and a final periapical radiograph (F)

A

B C

D E F

which continued root development results in a stronger tooththat is more resistant to fractures than one with thin root walls

In the past pulpotomy meant removal of pulp tissue to orbelow the cervical level Loss of pulp tissue in that area pre-

vents dentin formation which results in a weakened tooth thatis more prone to fracture In recent years a more conservativeand shallow pulpotomy has been popularized by Cvek and hassometimes been referred to as the Cvek technique52 Thisshallow or partial pulpotomy preserves all the radicular andmost of the coronal pulp tissue allowing more hard tissue todevelop in the root

The pulp may need to be removed to or below the cervicallevel when the entire crown of an immature tooth fracturesPulpotomy then is performed to encourage enough additionalroot development to allow subsequent crown restoration orpost and core construction to support a crown These situa-tions are relatively uncommon In recent years the techniquehas been modified to use mineral trioxide aggregate (MTA

eg ProRoot MTA [Tulsa Dental Products Tulsa Okla-homa]) instead of calcium hydroxide5556

Case SelectionBoth immature and mature teeth that can subsequently berestored with acid-etched composite can be treated with ashallow (partial) pulpotomy In general immature teeth aremore likely to be involved for the reasons stated previously

TechniqueThe shallow (partial) pulpotomy procedure (Fig 117) startswith induction of anesthesia and rubber dam isolation Theexposed dentin is washed with saline or sodium hypochloritesolution Extruding granulation tissue is removed with a

spoon excavator from the pulp wound site this provides anopportunity to determine more accurately the size and loca-tion of the exposure Next pulp tissue is removed to a depthof about 2 mm below the exposure This relatively smallamount of pulp removal is the reason the procedure is calleda shallow or partial pulpotomy

The procedure is accomplished using a water-cooled smallround diamond (about the size of a No 2 or No 4 round bur)in the high-speed handpiece Gently and gradually the surfacelayers of pulp tissue are wiped away beginning at the expo-sure site and extending into the pulp to a depth of about 2 mmbelow the exposure site

After the pulp has been amputated to the desired level adentin shelf is created surrounding the pulp wound Thewound is gently washed with sterile saline and hemostasiscan usually be expected within 5 minutes Then the wound is

washed again to remove the clot and is dressed with calciumhydroxide The remainder of the cavity is carefully sealedwith hard-setting cement such as glass ionomer When thecement has set the tooth may be restored with acid-etchedcomposite

Because calcium hydroxide liners disintegrate with timewhenever possible the tooth should be reentered after 6 to12 months to remove the initial calcium hydroxide layer andreplace it with a dentin bonding material This prevents micro-leakage at the site where the initial calcium hydroxide hasdeteriorated and produced a space between the new dentinbridge and the covering restoration

If MTA is used in place of calcium hydroxide it is notnecessary to wait for bleeding to stop completely The mate-

rial requires moisture for curing and can be placed directlyonto the pulp tissue Care must be taken to reduce the risk offorcing the material into the pulp proper the clinician shouldgently dab small increments of the material onto the pulpusing a moist cotton pellet The pulpotomy space is filled withMTA white powder so that it is completely flush with thefractured dentin surface The material is then allowed to curewhich may take 4 to 6 hours During the curing time it is notnecessary to protect the material with a restoration but thepatient must avoid using the tooth After curing the tooth maybe restored either with a composite resin or by bondingthe fractured crown segment back onto the tooth55 It is notnecessary to subsequently reenter the tooth because MTA isstable and does not break down in the manner of calcium

hydroxide

Treatment EvaluationTreatment is evaluated after 6 months and then yearly Suc-cessful shallow pulpotomy procedures may be considereddefinitive treatment and have a very good long-term successrate (Fig 118)5457

Root Canal Therapy Teeth with mature roots may undergo either pulpotomy or rootcanal therapy root canal therapy is usually necessary toaccommodate prosthetic requirements For example if the

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MANAGEMENT OF TRAUMATIC DENTAL INJURIES

1

Fig 117 Complicated crown fracture of the maxillary right central incisor The partial pulpotomy procedure is clinically

illustrated in the following steps A Pulp is exposed B pulpal tissue is excised 2 mm below the exposure C bleeding is

controlled by pressure only (cotton pellet moistened with saline) D hemostasis is obtained E white mineral trioxide aggregate

(MTA) seal is applied F protection of the MTA is achieved using a layer of glass ionomer lining

A B C

D E F

Fig 118 Six-month follow-up after partial pulpotomy Periapical radiograph (A) and sagittal view (B) obtained with conebeam computed tomography (CBCT)

A B

crown has fractured in the gingival margin region root canaltreatment allows post and core and crown placement

Crown-Root FracturesDescriptionCrown-root fractures are usually oblique and involve both thecrown and the root Anterior teeth show the so-called chisel-type fracture which splits the crown diagonally and extends

subgingivally to a root surface This type of fracture resemblesa crown fracture but is more extensive and more seriousbecause it includes the root Another variation is the fracturethat shatters the crown (Fig 119) The pieces are held in placeonly by the part of a fractured segment still attached to theperiodontal ligament In all of these fractures the pulp isusually exposed

In contrast to other traumatic injuries in which posteriorteeth are rarely involved crown-root fractures often include

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ENDODONTICS11

180

Emergency Care Teeth with crown-root fractures are often painful such inju-ries frequently require urgent care This may consist ofbonding loose tooth fragments but often includes pulp therapy

(Fig 1111) If the root is immature pulpotomy is preferableto pulpectomy whereas pulpectomy is the treatment of choicein patients with fully developed teeth (Fig 1112) Definitivetreatment should be postponed until an overall endodontic andrestorative treatment plan has been developed10

Treatment Planning Crown-root fractures are often complicated by pulp exposuresand extensive loss of tooth structure In the development of atreatment plan many questions must be considered

Which is better for this tooth pulpotomy orpulpectomy

After all loose fragments have been removed will therebe enough tooth structure to support a restoration Or

if the loose fragments are bonded in an immature toothwill it last until the alveolus has developed enough forplacement of an implant

Is the subgingival fracture below a level at which arestorative margin can be placed thus necessitating rootextrusion or gingivoplasty or alveoplasty

Should the tooth be extracted and replaced with a bridgeor implant Or if extraction is chosen can the space beclosed orthodontically

These are but a few of the many questions that must beanswered not only for crown-root fractures but also in othercomplicated trauma situations Because of the complexity of

the molars and premolars Cusp fractures that extend subgin-givally are common Diagnostically however they may bedifficult to identify in the early stages of development Simi-larly vertical fractures along the long axis of roots are difficult

to detect and diagnoseCrown-root fractures in posterior teeth cannot always be

associated with a single traumatic incident although bicycleor automobile accidents at times may produce these resultsThe risk is increased with a sharp blow to the chin causingthe jaws to slam together skin abrasions under the chin maybe a sign of such an impact Also all posterior teeth shouldbe examined with a sharp explorer to detect movement ofloose fragments

ExaminationCrown-root fractures are complex injuries that are difficultboth to evaluate and to treat Until recently it was recom-mended that all loose fragments be removed to evaluate the

extent of injury This may still be necessary in some instanceshowever with the availability of newer bonding agents it isnow possible to bond loose fragments at least temporarilyThe current recommendation is to attempt to bond loose frag-ments together particularly if the tooth is immature and stilldeveloping10 Clinical judgment must be used to decide whichcourse of action to follow

In a tooth with a crown that has been broken into severalpieces it is not unusual to find that this shattering effect alsohas extended to the root Additional radiographs at differentangles and CBCT imaging may help to identify radicularfracture lines (Fig 1110)748

Fig 119 A and B Buccal and lingual photographs of a crown and root fracture immediately upon presentation C and D

Images after removal of the fractured segments

A B

C D

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1

particularly in the apical regions of the roots (Fig 1113)5859 Recently May and colleagues demonstrated that CBCT ismost useful in cases in which conventional radiography yieldsinconclusive results or shows a fracture in the middle third ofa root60 In such cases CBCT may rule out or confirm anoblique course of fracture involving the cervical third in thelabiolingual dimension (Fig 1114)

Clinically root fractures may present as mobile or dis-placed teeth with pain on biting Symptoms are typicallymild If mobility and displacement of the coronal segmentare absent or slight the patient may have no chief complaintand may not seek treatment61 In general the more cervicalthe fracture the more mobility and displacement of thecoronal segment and the greater the likelihood of pulpnecrosis of this segment if it is not promptly repositionedSplinting is indicated in cervical and middle third rootfractures106263 Root fractures in the apical third usuallyrequire no immediate treatment but must be observedlong term62

these cases a team approach involving specialists in pediatricdentistry endodontics periodontics orthodontics oral andmaxillofacial surgery and prosthodontics is beneficial in thedevelopment of a treatment plan

Root FracturesDescriptionFractures of roots have been called intraalveolar root frac-tures horizontal root fractures and transverse root fractures They do not occur often and may be difficult to detect171358 Radiographically a root fracture is visualized if the x-raybeam passes through the fracture line Because these fracturesoften are transverse-to-oblique (involving pulp dentin andcementum) they may be missed if the central beamrsquos direc-tion is not parallel or close to parallel to the fracture line Forthis reason a steep vertical angle view is obtained in additionto the normal parallel angle whenever a root fracture is sus-pected This additional angle (ie foreshortened or occlusalview [approximately 45 degrees]) detects many fractures

Fig 1110 A and B Periapical radiographs demonstrating a crown fracture line C and D Sagittal and axial slides

confirming the presence and extension of the fractures lines (arrow)

A B

C D

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ENDODONTICS11

182

Fig 1111 Crown-root fracture of the maxillary left central incisor Emergency procedure for stabilization of the coronal

fragment using acid etchresin applied to the remaining tooth structure

A B

C D

Fig 1112 Crown-root fracture of the maxillary left central incisor treated with cervical pulpotomy A and B Periapical

radiographs at different horizontal angles C Two-month follow-up D Six-month follow-up

A B C D

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1

Fig 1113 Root fracture of the maxillary left central incisor A and B Immediate postoperative radiographs after reduction

and splinting C Six-month follow-up D Follow-up at 18 months

A B

C D

Emergency Care Initial treatment for root fracturesmdashrepositioning andstabilizationmdashshould be of acute priority for best results (Fig 1115) Repositioning of displaced coronal tooth segments iseasier if performed soon after the injury delayed reposition-ing may require orthodontic intervention to allow movementof the coronal segment into a desirable position

After repositioning the coronal tooth segment must besplinted to allow repair of the periodontal tissues (see Fig 1115) Four to 6 weeks of stabilization are usually sufficientunless the fracture location is close to the crest of the alveolarbone in which case longer splinting periods may be

advisable62 The outcome of the emergency care must bemonitored periodically

Sequelae of Root Fractures Root fractures are often characterized by the development ofcalcific metamorphosis (radiographic obliteration) in onesegment (usually the coronal) or both segments thereforeEPT readings may be very high or absent However in theabsence of other evidence of pulp necrosis (bony lesions later-ally at the level of the fracture or symptoms of irreversiblepulpitis or necrosis) lack of response to EPT by itself doesnot indicate a need for root canal treatment The majority of

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ENDODONTICS11

184

coronal portion that subsequently leads to inflammatorylesions adjacent to the fracture lines (Fig 1116)66 The end-odontic procedure when necessary usually is complex andreferral to a specialist should be considered In contrast to rootcanal treatment in most other endodontic situations when itis indicated for teeth with horizontal root fractures the

root fractures heal either spontaneously or after splinttherapy64-66 (see Fig 1113)

Root Canal Treatment Root canal treatment is indicated when pathosis is evidentusually owing to the development of pulp necrosis in the

Fig 1115 Root fracture of the maxillary right central incisor A and B Periapical radiograph and clinical photograph of the

tooth when the patient arrived at the emergency department C and D Reduction repositioning and splinting

A B

C D

Fig 1114 Root fracture of the maxillary left central incisor Cone beam computed tomography demonstrates the fracture in

all three planes axial (A) sagittal (B) and coronal (C)

A B C

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1

treatment is usually limited to the root canal in the coronalsegment to the fracture line The pulp in the apical segmentusually remains vital66-69

INJURIES TO THE PERIODONTIUM

Injuries to the periodontium involve trauma to the supportingstructures of teeth and often affect the neural and vascularsupply to the pulp The cause is usually a sudden impact such

as a blow or striking a hard object in a fall70 In general themore severe the degree of displacement the greater thedamage to the periodontium and to the dental pulp Table 112 provides a summary of the typical clinical and radiographicfindings associated with different types of injuries to theperiodontium

ConcussionWith concussion the tooth is sensitive to percussion onlyThere is no increase in mobility and the tooth has not beendisplaced The pulp may respond normally to testing and noradiographic changes are found10

Fig 1116 Root fracture of the maxillary right central incisor A Preoperative periapical radiograph B One month later after

removal of the splint Note the separation of the coronal and apical fragments Endodontic therapy of the coronal fragment wasinitiated C Two-year follow-up

A B C

Table 112 Differential diagnosis for the most common

injuries to the periodontium

Sensitivity topercussion Mobility Displacement

Concussion Yes No No

Subluxation Yes Yes No

Luxation Yes Yes Yes

SubluxationTeeth with subluxation injuries are sensitive to percussion andalso have increased mobility Although sulcular bleedingmight be present this clinical finding does not provide adiagnosis The teeth are not displaced and the pulp mayrespond normally to testing sometimes after initially failingto respond Radiographic findings are unremarkable10

LuxationLuxation is an injury to the supporting structures with loosen-

ing of the tooth and clinical or radiographic displacement Theinjury may displace the tooth in three possible directionsextrusive lateral or intrusive

Extrusive LuxationWith extrusive luxation teeth are partially displaced from thesocket along the long axis Extruded teeth have greatlyincreased mobility and radiographs show displacement Thepulp usually does not respond to testing101718

Lateral LuxationBy definition with lateral luxation the teeth may be displacedlingually buccally mesially or distally (ie away from theirnormal position in a horizontal direction) However because

the impact always comes from the facial aspect the crown isdisplaced lingually and the apex buccally creating a subse-quent alveolar fracture If the apex has been displaced into thesurrounding alveolar bone the tooth may be quite firm Ametallic sound on percussion might indicate that the root tiphas been forced into the alveolar bone

Intrusive LuxationWith intrusive luxation the teeth are forced into their socketsin an axial (apical) direction at times to the point of notbeing clinically visible They have no mobility resemblingankylosis71

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ENDODONTICS11

186

survival is good A pulp response that is absent initially andpresent at the second visit indicates a probable recovery ofvitality although cases of subsequent reversals have beennoted3173-75 If the pulp fails to respond both times the prog-nosis is questionable and the pulp status uncertain In theabsence of other findings indicating pulp necrosis the toothis retested in 3 to 4 months Continued lack of response mayindicate pulp necrosis by infarct but lack of response may not

be enough evidence to make a diagnosis of pulp necrosis Thatis the pulp may permanently lose sensory nerve supply butretain its blood supply After some time the pulp oftenresponds to testing if it recovers72

Radiographic EvaluationThe initial radiograph made after the injury will not disclosethe pulpal condition However it is important for evaluationof the general injury to the tooth and alveolus and serves asa basis for comparison for subsequent radiographs As dem-onstrated by Cohenca and colleagues48 the use of CBCT isvital in luxation injuries particularly lateral luxations inwhich a concomitant alveolar fracture is common The 3Dimaging allows for better diagnosis of alveolar fractures and

confirms the correct position of the tooth within the socketIn the case presented in Figs 1117 and 1118 the patient wasdiagnosed with a lateral luxation Although three differentperiapical radiographs failed to reveal the position of the toothin relation to its alveolus (Fig 1117) the CBCT scan clearlydemonstrated a cortical bone fracture and displacement of theapex toward the buccal aspect (Fig 1118)

Radiographs are also indicated for early diagnosis andtreatment of external resorptions and periradicular bonychanges Resorptive changes particularly external changesmay occur soon after injury if no attempt is made to arrestthe destructive process much of the root may be rapidly lostInflammatory (infection-related) resorption can be interceptedby timely endodontic intervention2372

Periodic radiographs show whether the root of a developingtooth is continuing to grow (a positive sign indicatingrecovery of the pulp) Another finding may be pulp space

Examination and DiagnosisThe clinical descriptions of the five types of luxation injuriesshould be sufficient to make the initial diagnosis Pulpal statusmust be continually monitored until a definitive diagnosis canbe made which in some cases may require several months oryears DDM and EPT are used in monitoring pulpal status 72

Concussion injuries generally respond to pulp testingBecause the injury is less severe the pulpal blood supply is

more likely to return to normalTeeth in the subluxation injury group also tend to retain or

recover pulpal responsiveness but less predictably than teethwith concussion injuries In both cases an immature toothwith an open apex usually has a good prognosis

Extrusive lateral and intrusive luxation injuries involvedisplacement of the teeth and therefore more damage to apicalvessels and nerves Pulp responses in teeth with extrusivelateral or intrusive luxations are often absent These pulpsoften do not recover responsiveness even if the pulp is vital(has blood supply) because sensory nerves may be perma-nently damaged Exceptions are immature teeth withwide-open apices these teeth often regain or retain pulp vital-ity (responsiveness to sensitivity tests) even after severe

injuries2372

Monitoring of pulpal status requires a schedule of pulptesting and radiographic evaluations for a long enough periodto permit determination of the outcome with a degree of cer-tainty (this may take 2 years or longer) Pulpal status is bestmonitored with pulp testing radiographic findings and obser-vation for developing symptoms and for crown colorchanges232572

Pulp Testing Sensitivity tests including cold (DDM) and EPT are used toevaluate the sensory response of teeth that have been injuredseveral adjacent and opposing teeth are included in the testAn initial lack of response is not unusual nor is a high reading

on the pulp tester Retesting is done in 4 to 6 weeks and theresults are recorded and compared with the initial responsesIf the pulp responds in both instances the prognosis for pulp

Fig 1117 A to C Periapical radiographs failed to reveal the position of the tooth in relation to its alveolus

A B C

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1

calcification or obliteration a common finding after luxationinjuries in immature teeth76 Also called calcific metamorpho-sis this canal obliteration may be partial or nearly complete(after several years) and does not indicate a need for root canaltreatment except when other signs and symptoms suggest pulpnecrosis76

Crown Color ChangesPulpal injury may cause discoloration even after only a fewdays Initial changes tend to be pink Subsequently if the pulpdoes not recover and becomes necrotic there may be a grayishdarkening of the crown often accompanied by a loss in trans-lucency (Fig 1119) In addition color changes may takeplace as a result of calcific metamorphosis of the pulp Suchcolor changes are likely to be yellow to brown and do notindicate pulp pathosis Other signs findings or symptoms arenecessary to diagnose pulp necrosis7276

Discoloration may be reversed This usually happens rela-tively soon after the injury and indicates that the pulp is vitalBecause of unpredictable changes associated with trauma-

tized teeth long-term evaluation is recommended72

Treatment of Luxation InjuriesLuxation injuries regardless of type often present diagnosticand treatment complexities that require consultation with spe-cialists For concussion injuries no immediate treatment isnecessary A soft diet is recommended for 2 weeks and ifpossible the patient should avoid biting until sensitivity hassubsided Pulpal status is monitored as described Subluxation may likewise require no treatment unless mobility is moder-ate if grade 2 mobility is present stabilization may be neces-sary for a short period (1 to 2 weeks)7778

Fig 1118 Cone beam computed tomography Transaxial volumetric reconstruction (A) and sagittal plane view (B)

demonstrating lateral luxation of the maxillary left central incisor with a concomitant alveolar fracture

A B

Fig 1119 Crown color changes as a result of pulpal injury after

a luxation injury buccal view (A) and lingual view (B)

A

B

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ENDODONTICS11

188

and to prevent additional resorption it is important to makeevery effort to disinfect the root canal system during rootcanal treatment It has been recommended that calciumhydroxide be placed in the canal for up to 2 weeks to aiddisinfection before the root canals are filled82

AvulsionDescription

An avulsed tooth is one that has been totally displaced fromits alveolar socket If the tooth is replanted soon after avulsion(immediate replantation) the periodontal ligament has a goodchance of healing Time out of socket and the storage mediumused are the critical factors in successful replantation It isimportant to preserve the periodontal ligament cells and thefibers attached to the root surface by keeping the tooth moistand minimizing handling of the root1183-86

Treatment Three situations involving avulsions may arise (1) an indi-vidual may telephone for advice about an avulsed tooth pre-senting an opportunity for immediate replantation (withinminutes) (2) a patient may be brought to the office with a

tooth that has been kept in a physiologic storage medium orosmolality-balanced medium andor stored dry (the extraoraldry time has been less than 60 minutes) or (3) the tooth hasbeen out for longer than 1 hour and has not been kept in astorage medium

Immediate ReplantationThe prognosis is improved by replantation immediately afteravulsion83-86 Many individuals (eg parents athletic instruc-tors and others) are aware of this emergency procedure andcan replant on-site Some may ask for advice by phone

When a patient who has had a tooth replanted at the acci-dent site comes to the dental office the replantation shouldbe examined both clinically and radiographically The dentist

looks for additional injuries to adjacent or opposing teeth andevaluates the replanted tooth for stability and alignment Theprocedure outlined in the next section is followed with theexception of the replantation step

Replantation Within 1 Hour of AvulsionmdashTooth with a Closed Apex If replantation is not feasible at the place of injury the injuredperson should be brought to the dental office and the toothtransported in such a way as to keep it moist118788 The mostcommon storage medium is Hanks Balanced Salt Solution(HBSS)89 which is commercially available as a kit (Save-a-Tooth Phoenix-Lazerus Pottstown Pennsylvania) Howeverif this is not available milk is an excellent alternative 89-92

Saliva is acceptable whereas water is not good for maintain-ing root-surface cell vitality83-86

When the patient arrives the following steps arerecommended

1 Place the tooth in a cup of physiologic saline whilepreparing for replantation

2 Take radiographs of the area of injury to look for evi-dence of alveolar fracture Consider the use of CBCTif indicated

3 Examine the avulsion site carefully for any loose bonefragments that may be removed If the alveolus is col-lapsed spread it open gently with an instrument

Fig 1120 Severe extrusive luxation The tooth was retained

only by soft tissue

Extrusive and lateral luxation injuries require repositioningand splinting The duration of splinting varies with the sever-ity of injury Extrusions may need only 2 weeks whereaslateral luxations that involve bony fractures need 4 weeks10 Professional judgment dictates variations from these recom-mendations Root canal treatment is indicated for teeth witha diagnosis of irreversible pulpitis or pulp necrosis Such adiagnosis often requires a combination of signs and symp-

toms such as discoloration of the crown lack of pulp responseto pulp testing and a periradicular lesion seen radiographi-cally10 However severe cases of either extrusive or lateralluxation of mature teeth might require endodontic therapywithin the first 2 weeks (Fig 1120)

Treatment of intrusive luxation injuries depends on rootmaturity7980 If the tooth is incompletely formed with an openapex it may reposition spontaneously A clinical studyrevealed that in young patients 12 to 17 years old who havecomplete root formation spontaneous re-eruption is possibleand was found to be the best treatment with regard to marginalperiodontal healing80 In older patients (ie older than17 years) with complete root formation either surgical ororthodontic extrusion should be attempted Root canal treat-

ment is indicated for intruded teeth with the exception of thosewith immature roots in which case the pulp may revascular-ize81 The patient must be monitored carefully because com-plications such as failure of pulpal healing usually aresymptomless If radiographic evidence indicates pulp necrosis(lack of continued root development) root canal treatmentshould be performed10

Root canal therapy is indicated for luxated teeth in whichthe pulps become necrotic Often in luxated teeth there hasbeen damage to the root cementum if the pulps becomeinfected external resorption is stimulated by the presence ofbacteria in the pulp space To arrest any ongoing resorption

11-1

httpdentalebookscom





1 Examine the area of tooth avulsion and examine theradiographs for evidence of alveolar fractures

2 Remove debris and pieces of soft tissue adhering to theroot surface using a dry piece of gauze

3 In cases of delayed replantation root canal treatmentshould be carried out on the tooth either prior to replan-

tation or 7 to 10 days later as in other replantationsituations

4 Suction the alveolar socket carefully to remove theblood clot and irrigate the socket with saline

5 Replant the tooth gently into the socket checking forproper alignment and occlusal contact

6 Apply a flexible splint (wires up to 0016 inch [04 mm])for 4 weeks

Soaking the tooth in a 24 solution of sodium fluoride(acidulated to a pH of 55) for 20 minutes has been suggestedto slow down osseous replacement99 but this should not beseen as an absolute recommendation

Patient Instructions

Antibiotics are recommended for patients with replantedavulsed teeth100 In patients 12 years of age or older doxycy-cline 100 mg two times per day for 7 days is the currentrecommendation Alternatively amoxicillin 500 mg threetimes per day for 7 days can be prescribed For children underthe age of 12 penicillin V 25 to 50 mgkg of body weight individed doses every 6 hours for 7 days can be prescribed11 Atetanus booster injection is recommended if the previous onehad been administered more than 5 years earlier19 Supportivecare is important Instruct the patient (and parents) to use asoft diet for up to 2 weeks to brush with a soft toothbrushafter every meal and to use a chlorhexidine mouth rinse(012) twice a day for a week

Sequelae of Dental Trauma Pulp NecrosisWhen the pulp is diagnosed as necrotic the main factor to beconsidered is the stage of root development If the root is fullymatured root canal therapy is the treatment of choice Inimmature teeth with open apexes treatment options includeapexification and pulp revascularization

Classic apexification refers to long-term use of calciumhydroxide for up to 18 months However such a long treat-ment process may result in crown-root fracture at the cervicalarea (thin weak dentinal walls) and lack of a an immediatepermanent and esthetic restoration

Several procedures and materials have been used toinduce root-end barrier formation In 2001 Witherspoon

and Ham reported promising results when using MTAin single-visit apexification treatment of immature teethwith necrotic pulps101 Moreover the use of an intracanalmedication is not necessary when MTA is used as an apicalplug

Pulp revascularization procedures for the treatment ofimmature teeth with necrotic pulps and apical periodontitish i d h tt ti lt f i lt

4 Irrigate the socket gently with saline to remove con-taminated coagulum

5 Grasp the crown of the tooth with extraction forceps toavoid handling the root

6 Examine the tooth for debris and if present gentlyremove it with saline from a syringe

7 Using the forceps partially insert the tooth into thesocket gentle finger pressure can be used for complete

seating of the tooth or the patient can bite on a pieceof gauze to accomplish the seating

8 Check for proper alignment and correct any hyperoc-clusion Soft tissue lacerations should be tightly suturedparticularly cervically

9 Stabilize the tooth for 2 weeks with a flexible splintnylon stainless steel or nickel-titanium wires up to0016 inch (04 mm) in diameter are significantly moreflexible93

Replantation Within 1 Hour of AvulsionmdashTooth with an Open Apex When the patient arrives the following steps arerecommended


2 Administer a local anesthetic3 Examine the alveolar socket looking for fracture of the

socket wall4 If available cover the root surface topically with a

tetracycline-based antibiotic before replanting thetooth1194-98

5 Replant the tooth with slight digital pressure6 Suture gingival lacerations especially in the cervical

area7 Verify normal position of the replanted tooth8 Apply a flexible splint (wires up to 0016 inch [04 mm])

for 2 weeks

For children younger than 9 years Amoxicillin to 50 mg kg in divided doses every 8 hours for 7 days can be prescribedA tetanus booster injection is recommended if the previousone was administered more than 5 years earlier

Root canal treatment is indicated for mature teeth andshould be done optimally after 1 week and before the splintis removed (the splint stabilizes the tooth during the proce-dure) Timing is crucial in preventing the onset and progres-sion of external inflammatory root resorption The exceptionsto routine root canal therapy are immature teeth withwide-open apices they may revascularize but must beevaluated at regular intervals of 2 6 and 12 months afterreplantation If subsequent evaluations indicate pulp necrosisroot canal treatment probably including apexification is

indicated1194

Replantation with Dry Time Longer Than 60MinutesmdashTooth with a Closed Apex If a tooth has been out of the alveolar socket for longer than1 hour (and has not been kept moist in a suitable medium)periodontal ligament cells and fibers will not survive regard-l f th t f t d l t R l t t





Endodontics





School of Dentistry









School of Dentistry


Baltimore Maryland



Printed in China








Notices






ISBN 978-1-4557-5410-6



v

Contributors














Seattle Washington



Iowa City Iowa




ENDODONTICS

vi
















Berkeley California









viii

Preface

















1

1








function










age


tissues



Pulp Function

Morphology



Blood Vessels

Innervation




CHAPTER OUTLINE

LEARNING OBJECTIVES









1-1



ENDODONTICS1

2














OE

A

DL

B

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DF

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ED

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C PDL

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Pulp horn

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Root canal

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5






















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6






BA





Primary dentin

SD SD

Primary dentin

BA

DC

PULP FUNCTION








7









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Primary dentin

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RPD

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D

C



ENDODONTICS1

8

Sensation


MORPHOLOGY








DB













9

Odontoblast

Lymphaticvessel

Dendritic cell

Macrophage

Plasma cell

Stem cell

A

Fibroblast

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Nerve

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layer

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A



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A

B

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1



patient

A

B




capillary beds

Arteriole

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Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

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1








A B C














httpdentalebookscom



ENDODONTICS11

186












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A B C

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1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




Printed in China








Notices






ISBN 978-1-4557-5410-6



v

Contributors














Seattle Washington



Iowa City Iowa




ENDODONTICS

vi
















Berkeley California









viii

Preface

















1

1








function










age


tissues



Pulp Function

Morphology



Blood Vessels

Innervation




CHAPTER OUTLINE

LEARNING OBJECTIVES









1-1



ENDODONTICS1

2














OE

A

DL

B

Bud EM

C

DF

DP

D

OD

BV




3



















DP

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A

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4







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C PDL

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Pulp horn

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5






















ENDODONTICS1

6






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Primary dentin

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Primary dentin

BA

DC

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7









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D

C



ENDODONTICS1

8

Sensation


MORPHOLOGY








DB













9

Odontoblast

Lymphaticvessel

Dendritic cell

Macrophage

Plasma cell

Stem cell

A

Fibroblast

Capillary

Nerve

Dentin

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layer

Capillaries

Predentin

B

CFZCRZ

C















1











BLOOD VESSELS




















B

A



ENDODONTICS1

12











Lymphatics2627



Trowbridge)

A

B

C




1



patient

A

B




capillary beds

Arteriole

Metarteriole

Capillaries

Small venule

VenuleLymphvessel


Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

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1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

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B

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ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




v

Contributors














Seattle Washington



Iowa City Iowa




ENDODONTICS

vi
















Berkeley California









viii

Preface

















1

1








function










age


tissues



Pulp Function

Morphology



Blood Vessels

Innervation




CHAPTER OUTLINE

LEARNING OBJECTIVES









1-1



ENDODONTICS1

2














OE

A

DL

B

Bud EM

C

DF

DP

D

OD

BV




3



















DP

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5






















ENDODONTICS1

6






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7









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ENDODONTICS1

8

Sensation


MORPHOLOGY








DB













9

Odontoblast

Lymphaticvessel

Dendritic cell

Macrophage

Plasma cell

Stem cell

A

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layer

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C















1











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B

A



ENDODONTICS1

12











Lymphatics2627



Trowbridge)

A

B

C




1



patient

A

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capillary beds

Arteriole

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Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



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C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



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httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

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B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

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for 2 weeks



indicated1194




ENDODONTICS

vi
















Berkeley California









viii

Preface

















1

1








function










age


tissues



Pulp Function

Morphology



Blood Vessels

Innervation




CHAPTER OUTLINE

LEARNING OBJECTIVES









1-1



ENDODONTICS1

2














OE

A

DL

B

Bud EM

C

DF

DP

D

OD

BV




3



















DP

IDE

A

DP AOD

B

OB

A

D

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ENDODONTICS1

4







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Pulp horn

Pulp chamber

Root canal

Lateral canal

Apical foramen




5






















ENDODONTICS1

6






BA





Primary dentin

SD SD

Primary dentin

BA

DC

PULP FUNCTION








7









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D

C



ENDODONTICS1

8

Sensation


MORPHOLOGY








DB













9

Odontoblast

Lymphaticvessel

Dendritic cell

Macrophage

Plasma cell

Stem cell

A

Fibroblast

Capillary

Nerve

Dentin

Odontoblast

layer

Capillaries

Predentin

B

CFZCRZ

C















1











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B

A



ENDODONTICS1

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Lymphatics2627



Trowbridge)

A

B

C




1



patient

A

B




capillary beds

Arteriole

Metarteriole

Capillaries

Small venule

VenuleLymphvessel


Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

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1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

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1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

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httpdentalebookscom



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186












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A B C

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A B



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B

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ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

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for 2 weeks



indicated1194




viii

Preface

















1

1








function










age


tissues



Pulp Function

Morphology



Blood Vessels

Innervation




CHAPTER OUTLINE

LEARNING OBJECTIVES









1-1



ENDODONTICS1

2














OE

A

DL

B

Bud EM

C

DF

DP

D

OD

BV




3



















DP

IDE

A

DP AOD

B

OB

A

D

C



ENDODONTICS1

4







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HERS

EDE

C

HERS

ED

D

BA



C PDL

AB

D





Pulp horn

Pulp chamber

Root canal

Lateral canal

Apical foramen




5






















ENDODONTICS1

6






BA





Primary dentin

SD SD

Primary dentin

BA

DC

PULP FUNCTION








7









RCD

Primary dentin

RPD

RPD

A B

D

C



ENDODONTICS1

8

Sensation


MORPHOLOGY








DB













9

Odontoblast

Lymphaticvessel

Dendritic cell

Macrophage

Plasma cell

Stem cell

A

Fibroblast

Capillary

Nerve

Dentin

Odontoblast

layer

Capillaries

Predentin

B

CFZCRZ

C















1











BLOOD VESSELS




















B

A



ENDODONTICS1

12











Lymphatics2627



Trowbridge)

A

B

C




1



patient

A

B




capillary beds

Arteriole

Metarteriole

Capillaries

Small venule

VenuleLymphvessel


Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

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1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

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1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



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ENDODONTICS11

186












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A B C

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1








A B



A

B

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ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

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for 2 weeks



indicated1194




1

1








function










age


tissues



Pulp Function

Morphology



Blood Vessels

Innervation




CHAPTER OUTLINE

LEARNING OBJECTIVES









1-1



ENDODONTICS1

2














OE

A

DL

B

Bud EM

C

DF

DP

D

OD

BV




3



















DP

IDE

A

DP AOD

B

OB

A

D

C



ENDODONTICS1

4







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HERS

EDE

C

HERS

ED

D

BA



C PDL

AB

D





Pulp horn

Pulp chamber

Root canal

Lateral canal

Apical foramen




5






















ENDODONTICS1

6






BA





Primary dentin

SD SD

Primary dentin

BA

DC

PULP FUNCTION








7









RCD

Primary dentin

RPD

RPD

A B

D

C



ENDODONTICS1

8

Sensation


MORPHOLOGY








DB













9

Odontoblast

Lymphaticvessel

Dendritic cell

Macrophage

Plasma cell

Stem cell

A

Fibroblast

Capillary

Nerve

Dentin

Odontoblast

layer

Capillaries

Predentin

B

CFZCRZ

C















1











BLOOD VESSELS




















B

A



ENDODONTICS1

12











Lymphatics2627



Trowbridge)

A

B

C




1



patient

A

B




capillary beds

Arteriole

Metarteriole

Capillaries

Small venule

VenuleLymphvessel


Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




ENDODONTICS1

2














OE

A

DL

B

Bud EM

C

DF

DP

D

OD

BV




3



















DP

IDE

A

DP AOD

B

OB

A

D

C



ENDODONTICS1

4







IDE

HERS

EDE

C

HERS

ED

D

BA



C PDL

AB

D





Pulp horn

Pulp chamber

Root canal

Lateral canal

Apical foramen




5






















ENDODONTICS1

6






BA





Primary dentin

SD SD

Primary dentin

BA

DC

PULP FUNCTION








7









RCD

Primary dentin

RPD

RPD

A B

D

C



ENDODONTICS1

8

Sensation


MORPHOLOGY








DB













9

Odontoblast

Lymphaticvessel

Dendritic cell

Macrophage

Plasma cell

Stem cell

A

Fibroblast

Capillary

Nerve

Dentin

Odontoblast

layer

Capillaries

Predentin

B

CFZCRZ

C















1











BLOOD VESSELS




















B

A



ENDODONTICS1

12











Lymphatics2627



Trowbridge)

A

B

C




1



patient

A

B




capillary beds

Arteriole

Metarteriole

Capillaries

Small venule

VenuleLymphvessel


Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194





3



















DP

IDE

A

DP AOD

B

OB

A

D

C



ENDODONTICS1

4







IDE

HERS

EDE

C

HERS

ED

D

BA



C PDL

AB

D





Pulp horn

Pulp chamber

Root canal

Lateral canal

Apical foramen




5






















ENDODONTICS1

6






BA





Primary dentin

SD SD

Primary dentin

BA

DC

PULP FUNCTION








7









RCD

Primary dentin

RPD

RPD

A B

D

C



ENDODONTICS1

8

Sensation


MORPHOLOGY








DB













9

Odontoblast

Lymphaticvessel

Dendritic cell

Macrophage

Plasma cell

Stem cell

A

Fibroblast

Capillary

Nerve

Dentin

Odontoblast

layer

Capillaries

Predentin

B

CFZCRZ

C















1











BLOOD VESSELS




















B

A



ENDODONTICS1

12











Lymphatics2627



Trowbridge)

A

B

C




1



patient

A

B




capillary beds

Arteriole

Metarteriole

Capillaries

Small venule

VenuleLymphvessel


Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




ENDODONTICS1

4







IDE

HERS

EDE

C

HERS

ED

D

BA



C PDL

AB

D





Pulp horn

Pulp chamber

Root canal

Lateral canal

Apical foramen




5






















ENDODONTICS1

6






BA





Primary dentin

SD SD

Primary dentin

BA

DC

PULP FUNCTION








7









RCD

Primary dentin

RPD

RPD

A B

D

C



ENDODONTICS1

8

Sensation


MORPHOLOGY








DB













9

Odontoblast

Lymphaticvessel

Dendritic cell

Macrophage

Plasma cell

Stem cell

A

Fibroblast

Capillary

Nerve

Dentin

Odontoblast

layer

Capillaries

Predentin

B

CFZCRZ

C















1











BLOOD VESSELS




















B

A



ENDODONTICS1

12











Lymphatics2627



Trowbridge)

A

B

C




1



patient

A

B




capillary beds

Arteriole

Metarteriole

Capillaries

Small venule

VenuleLymphvessel


Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194





5






















ENDODONTICS1

6






BA





Primary dentin

SD SD

Primary dentin

BA

DC

PULP FUNCTION








7









RCD

Primary dentin

RPD

RPD

A B

D

C



ENDODONTICS1

8

Sensation


MORPHOLOGY








DB













9

Odontoblast

Lymphaticvessel

Dendritic cell

Macrophage

Plasma cell

Stem cell

A

Fibroblast

Capillary

Nerve

Dentin

Odontoblast

layer

Capillaries

Predentin

B

CFZCRZ

C















1











BLOOD VESSELS




















B

A



ENDODONTICS1

12











Lymphatics2627



Trowbridge)

A

B

C




1



patient

A

B




capillary beds

Arteriole

Metarteriole

Capillaries

Small venule

VenuleLymphvessel


Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




ENDODONTICS1

6






BA





Primary dentin

SD SD

Primary dentin

BA

DC

PULP FUNCTION








7









RCD

Primary dentin

RPD

RPD

A B

D

C



ENDODONTICS1

8

Sensation


MORPHOLOGY








DB













9

Odontoblast

Lymphaticvessel

Dendritic cell

Macrophage

Plasma cell

Stem cell

A

Fibroblast

Capillary

Nerve

Dentin

Odontoblast

layer

Capillaries

Predentin

B

CFZCRZ

C















1











BLOOD VESSELS




















B

A



ENDODONTICS1

12











Lymphatics2627



Trowbridge)

A

B

C




1



patient

A

B




capillary beds

Arteriole

Metarteriole

Capillaries

Small venule

VenuleLymphvessel


Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194





7









RCD

Primary dentin

RPD

RPD

A B

D

C



ENDODONTICS1

8

Sensation


MORPHOLOGY








DB













9

Odontoblast

Lymphaticvessel

Dendritic cell

Macrophage

Plasma cell

Stem cell

A

Fibroblast

Capillary

Nerve

Dentin

Odontoblast

layer

Capillaries

Predentin

B

CFZCRZ

C















1











BLOOD VESSELS




















B

A



ENDODONTICS1

12











Lymphatics2627



Trowbridge)

A

B

C




1



patient

A

B




capillary beds

Arteriole

Metarteriole

Capillaries

Small venule

VenuleLymphvessel


Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




ENDODONTICS1

8

Sensation


MORPHOLOGY








DB













9

Odontoblast

Lymphaticvessel

Dendritic cell

Macrophage

Plasma cell

Stem cell

A

Fibroblast

Capillary

Nerve

Dentin

Odontoblast

layer

Capillaries

Predentin

B

CFZCRZ

C















1











BLOOD VESSELS




















B

A



ENDODONTICS1

12











Lymphatics2627



Trowbridge)

A

B

C




1



patient

A

B




capillary beds

Arteriole

Metarteriole

Capillaries

Small venule

VenuleLymphvessel


Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194





9

Odontoblast

Lymphaticvessel

Dendritic cell

Macrophage

Plasma cell

Stem cell

A

Fibroblast

Capillary

Nerve

Dentin

Odontoblast

layer

Capillaries

Predentin

B

CFZCRZ

C















1











BLOOD VESSELS




















B

A



ENDODONTICS1

12











Lymphatics2627



Trowbridge)

A

B

C




1



patient

A

B




capillary beds

Arteriole

Metarteriole

Capillaries

Small venule

VenuleLymphvessel


Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194







1











BLOOD VESSELS




















B

A



ENDODONTICS1

12











Lymphatics2627



Trowbridge)

A

B

C




1



patient

A

B




capillary beds

Arteriole

Metarteriole

Capillaries

Small venule

VenuleLymphvessel


Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




ENDODONTICS1

12











Lymphatics2627



Trowbridge)

A

B

C




1



patient

A

B




capillary beds

Arteriole

Metarteriole

Capillaries

Small venule

VenuleLymphvessel


Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194





1



patient

A

B




capillary beds

Arteriole

Metarteriole

Capillaries

Small venule

VenuleLymphvessel


Arteriovenousshunt

Vascular smooth

muscle cells










ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




ENDODONTICS1



V

A

BA

DC






INNERVATION






1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194





1


from both divisions















L





fibers (CO)



ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




ENDODONTICS1

16


















A

B


with silver




1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194





1


























A B C



ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




ENDODONTICS1

18
















AB

PDL

C

H







1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194





1














PDL

ERM

A

B






ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




ENDODONTICS1

20

REFERENCES




1987



24939 1980






















Res 158 2001





31643 1986




1)384 1998




2007












J Dent Ed 67678 2003



Soc 88345 1992









224154 1989










2002



(Basel) 140329 1991






Dent Res 85488-495 2006





1990






Scand 37339 1979





39(suppl 1)3S-11S 1994






249 2000



2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




2








formation


on the pulp




therapy


developing roots





(apexification)


root-end closure






Definitions




The Open Apex


and promoting


CHAPTER OUTLINE

LEARNING OBJECTIVES

DEFINITIONS









ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




ENDODONTICS11

178




A

B C

D E F















hydroxide



httpdentalebookscom




1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194





1





A B C

D E F


A B





httpdentalebookscom



ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




ENDODONTICS11

180


















A B

C D

httpdentalebookscom




1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194





1







A B

C D

httpdentalebookscom



ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




ENDODONTICS11

182



A B

C D



A B C D

httpdentalebookscom




1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194





1



A B

C D





httpdentalebookscom



ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




ENDODONTICS11

184






A B

C D



A B C

httpdentalebookscom




1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194





1








A B C














httpdentalebookscom



ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




ENDODONTICS11

186












injuries2372





A B C

httpdentalebookscom




1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194





1








A B



A

B

httpdentalebookscom



ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194




ENDODONTICS11

188


AvulsionDescription














only by soft tissue






11-1

httpdentalebookscom


































for 2 weeks



indicated1194



































for 2 weeks



indicated1194


2015 endodontics principles and practice 5th edition

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