Loyola University ChicagoLoyola eCommons

Master's Theses Theses and Dissertations

1978

The Effect of a Calcium Hydroxide Paste onResorption of Replanted Teeth in DogsDale Marshall AndersonLoyola University Chicago

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This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.Copyright © 1978 Dale Marshall Anderson

Recommended CitationAnderson, Dale Marshall, "The Effect of a Calcium Hydroxide Paste on Resorption of Replanted Teeth in Dogs" (1978). Master'sTheses. Paper 2978.http://ecommons.luc.edu/luc_theses/2978

THE EFFECT OF A CALCIUM HYDROXIDE PASTE ON

RESORPTION OF REPLANTED TEETII IN DOGS

by

Dale M. Anderson, B.S., D.D.S.

A Thesis Submitted to the Faculty of the Graduate School of

Loyola University of Chicago in Partial Fulfillment

of the Requirements for the Degree of

Master of Science

April

1978

_ ___..- ;[:1BRAl::,'("i -­

OOYOl ~ ' n\11'· ,n:: "" '. '

DEDICATION

To my parents, Marshall and Virginia Anderson,

whose love and guidance have meant so much to me, to

my wife, Kathy, for her love and understanding, and to

her parents, David and Lotta Borgardt, for their love

and constant support.

ii

ACKNOWLEDGMENTS

To Dr. Bruce Felder and Dr. John Gillan, whose

hard work and moral support allowed this research to

be completed.

To Dr. Norman Wood, whose abilities, knowledge,

and integrity hopefully have rubbed off on me during the

years I have known him.

To Dr. John Madonia, teacher, administrator, and

friend to all his students.

To Dr. Marshall Smulson, whose guidance and friend­

ship has gone far beyond the field of endodontics.

To Dr. Franklin Weine for his friendship, excellence

in teaching and personal counsel.

iii

VITA

The author, Dale Marshall Anderson, is the son

of Nels Marshall and Virginia Ruth Anderson. He was

born in Chicago, Illinois, on May 18, 1949.

He received his elementary education at West

Northfield School in Northbrook, Illinois, and his

secondary education at Glenbrook North High School,

where he was a member of the National Honor Society,

and graduated in June of 1966. In September of the

same year he entered Wheaton College, Wheaton, Illinois,

where he received a Bachelor of Science degree in June

of 1970 with a major in Biology.

In September of 1970 he entered the Loyola

University School of Dentistry (Chicago College of

Dental Surgery,) where he graduated in June of 1974

with the degree of Doctor of Dental Surgery. Honors

included Omicron Kappa Upsilon national dental honor

society, and the American Academy of Oral Medicine

award.

After receiving his D.D.S. degree, he was in

private dental practice in Palatine, Illinois from

August, 1974 to August, 1976. He held the position of

part-time Clinical Instructor in the Department of Oral

Diagnosis at Loyola University School of Dentistry from

December, 1975 until August, 1976, when he began the

iv

graduate program at the same institution, pursuing the

degree of Master of Science in Oral Biology and a

specialty certificate in the Department of Endodontics.

v

DEDICATION . . .

ACKNOWLEDGEMENTS •

TABLE OF CONTENTS

I I I I I I I I I I I I I I I

. . . . . • • • • . . . . . . . VITA •• . . . . . . • • . . . • • 0 • . . . . . . TABLE OF CONTENTS I I I I I I I I I I I I I I I I

LIST OF TABLES • . . . . . . . . . . . . . . LIST OF FIGURES

Chapter

. . . . . . . . . . . . . . . . .

I. INTRODUCTION . . . • • . • • . • • • • .

II. REVIEW OF THE LITERATURE • • • . . • . .

III. MATERIALS AND METHODS . . . . . . . . . IV.

v. RESULTS . . . DISCUSSION • •

SUMMARY AND CONCLUSIONS

• • • . . . . . . . . • • • • • • . . . . . . . . . . . . . . . . . . . .

REFERENCES • • I I I I 0 • • • • • . . . . • •

FIGURES 0 I 0 I 0 0 0 0 I 0 I I 0 I I I I I I 1 I

vi

Page

ii

iii

iv

vi

vii

viii

1

3

47

54

71

80

82

97

LIST OF TABLES

Table Page

1 0 Results, Dog Number One 0 0 0 0 0 0 0 0 0 62

2o Results, Dog Number Two 0 0 0 0 0 0 0 0 0 0 0 63

3o Results, Dog Number Three 0 0 0 0 0 0 0 0 0 0 64

4o Results, Dog Number Four 0 0 0 0 0 0 0 0 0 0 65

5o Results, Dog Number Five 0 0 0 0 0 0 0 0 0 0 66

6o Results, Dog Number Six 0 0 0 0 0 0 0 0 0 0 0 67

7o Summarized Histologic Scores 0 0 0 0 0 0 0 0 68

8o Statistical Analysis 0 0 0 0 0 0 0 0 0 0 0 0 69

9o Comparison of Contralateral Gutta-Percha and Ca(OH)2 Filled Teeth 0 0 0 0 0 0 0 0 0 0 70

vii

LIST OF FIGURES

Figure Page

1. 99

2. 99

3. 101

4. 101

5. 103

6. 103

7. 105

8. 105

9. 107

10. 107

11. 109

12. 109

13. • 111

14. 111

15. 113

16. 113

17. 115

18. 115

1 9. "117

viii

CHAPTER I

INTRODUCTION

Proper treatment of traumatic injuries has always

been a particular problem in dentistry as well as

medicine, because of the need for quick, decisive,

and correct treatment. Emergency treatment, often

rendered in the middle of an already hectic day, may

have long lasting negative effects on the unfortunate

patient presenting to his dentist with his teeth in

his hand after an accident, especially if the treatment

rendered is inadequate or incorrect. Although replant-

ation of avulsed teeth has been practiced for centuries,

only in the last twenty years has proper research on

the effect of the many contradictory methods of treat-

ment begun to change tooth replantation from a pessi-

mistic temporary measure to a more predictable procedure.

Although adults may suffer tooth avulsion, often

as the result of automobile accidents or physical

altercations, children may suffer severe psychological

trauma in addition to the physical injury. Children

most frequently lose teeth due to sports accidents or

overexuberant roughhousing. Because anatomical consider-

ations usually prevent the construction of fixed bridge­

work in children and young teenagers,these youngsters 1

2

are forced to wear bulky and often unaesthetic removable

acrylic appliances for years. Therefore, it is fortunate

that the replantation procedure is being refined by

isolating the pertinent variables and determining

which methods lead to increased success. Healthy re­

tention of these teeth through the formative years,

when the emotional impact of the loss of anterior teeth

may mean severe impairment of the psychosocial develop­

ment of a child, may soon become a predictable procedure.

Root resorption is a likely sequela of tooth

replantation, and is probably the most common reason

for failure in these cares (1). Endodontic therapy using

gutta-perrna and sealer as a filling technique is

commonly performed on replanted teeth, but several recent

studies have reported either prevention or arrest of

external resorption by using calcium hydroxide as an

intermediate root canal filling material. The purpose

of this study is to determine histologically and

radiographically, using dogs as an experimental model,

whether teeth replanted with a calcium hydroxide paste

in the root canals show any difference in incidence or

severity of external resorption from teeth conventionally

filled with gutta-percha and sealer.

CHAPTER II

REVIEW OF THE LITERATURE

Replantation of teeth has been defined as "the

return of a tooth avulsed by acute trauma, into its

alveolus." (2) Grossman (3) defined intentional

replantation as "the intentional removal of a tooth

and its reinsertion into its socket after endodontic

manipulation or obturation of the canals or both,"

and transplantation as "the removal of a tooth from

one socket and insertion into another socket of the

same or a different person." The literature pertaining

to these three different modes of reinsertion of teeth

into empty sockets shows much overlapping of research

methods, applicable results, and healing processes,

so although there are many important differences

between replantation of avulsed teeth, intentional

replantation, and transplantation, any review of the

literature in the first area would be incomplete without

including selected articles from the other two areas.

Albucasis made the first reference in the liter­

ature to replantation in 1050, so it has been attempted

for hundreds of years. The first research on the subject

was reported in 1775 by Hunter (4), who reached the con­

clusion that a vital periodontal ligament was a pre­

requisite for successful replantation. In order to

3

prolong the life of recently extracted teeth, he planted

them in the comb of a rooster, until such time as he

would have occasion to use them. Barbikow reported

that in Elizabethan times, it was fashionable for

socialites to have the extracted teeth of paupers

transplanted into their mouths. An increase in the

incidence of tuberculosis and syphilis and other infec­

tious diseases, however, brought this practice to an

end. (5)

Even against resistance from those who supported

the focal infection theory and advocated extraction of

all "pulpless" teeth, preliminary research into tooth

replantation began to appear in the literature in the

third decade of this century. Wilkinson (6), in 1926,

extracted two monkey lateral incisors and replanted them

five days later. Postoperative examination after 53 days

showed root resorption. Skillen and Lundquist (7), in

1929, found more promising results. They replanted

teeth in dogs and found normal reattachment through

formation of cementum. B5decker and Lefkowitz (8), in

1935, however, extracted anterior teeth in six dogs,

placed retrograde amalgam fillings, while keeping teeth

moist with sterile saline, and replanted the teeth within

thirty minutes. Microscopic examination revealed areas

of resorption which they equated with "areas of infec­

tion," so they concluded that "this procedure would

4

probably not come into vogue again because of the real

dangers of focal infection in human teeth." The impact

of this study may be one of the reasons why very little

research was done on replantation until the 1950's, when

the focal infection theory rapidly lost acceptance,

at least pertaining to teeth with proper endodontic

therapy.

Intentional extraction and replantation of teeth

was described by Grossman (3), 1966, as being performed

when problems encountered in conventional endodontic

therapy preclude successful therapy. Such problems as

broken instruments lodged in the canal, root perforati~n,

excessive canal curvature, or blockage of the canal were

depicted. It is used as an alternative to extraction

5

and prosthetic replacement. When teeth were kept moist

with a saline antibiotic solution during extraoral

treatment, he reported that 36 out of 45 replantations

done intentionally were successful, with no root resorp­

tion, at an average of 5.6 years recall time. Emmertsen,

et al (9) the same year reported on 100 molars with

inaccessable canals and periapical pathosis that were

extracted, kept moist with saline, and treated from the

apical end and filled with either amalgam or gutta-percha,

and replanted after curettage of the periapical area.

The teeth were splinted for eight days and radio­

graphed for up to thirteen years. Only 34% showed

periapical healing and absence of root resorption at

one year, but they reported that teeth with periapical

radiolucencies at time of replantation showed signifi­

cantly less root resorption than those without. Also,

patients less than 30 years of age had inflammatory

root resorption and periapical inflammation more fre­

quently than older age groups. Kaplan and Ward (10)

in 1971 suggested that repositioning of malposed or

rotated teeth, and replantation after extraction of

6

the wrong tooth, were two additional indications for

intentional replantation, and listed as contraindications

systemic healing problems, loss of crestal bone, root

fractures, destruction of labial plate of bone, and

hypercementosis. Simon and Kimura (11) in 1974 extracted

teeth, treated the roots endodontically, and replanted

them in their sockets, the crowns being cut off below the

level of the crestal bone, in an attempt to maintain the

height and width of alveolar bone for the support of

prosthetic appliances. Eighteen month postoperative

clinical and radiographic findings indicated that although

no bone formed coronal to the roots, and many of the roots

were resorbing, clinically some cases appeared to be

maintaining bone to different degrees. Simon, et al, (12)

the next year, in a histologic study of the same or

similar teeth, showed normal periodontal ligament,

resorption, ankylosis, and repaired tooth structure,

without predictability as to location or severity. They

also described an eosinophilic cuticle-like band found

between the epithelium covering replanted dentin surfaces

artd the resorbed dentin. Even though the success rates

reported for most of the intentional replantation studies

are not particularly high, a report by Kirsten (13) of

an intentional replant done in 1938, successful for 25

years, makes it seem a reasonable alternative to extrac­

tion and replacement in selected cases.

Transplantation of teeth from one socket to another

is classified by Natiella, et·al (14) as being either

autogenous (in the same individual), homogenous (within

7

the same species), or heterogenous (one species to another).

The same authors give the overall rate of success for

antogenous transplants as greater than fifty per cent.

Schulman, et al (15) studied autogenous transplants

(maxillary left central incisor to right central's

socket) and allogeneic (the same as homogenous) trans­

plants, and found that while the autogenous grafts

rapidly reattached by normal periodontal ligament, the

allografts became firm as a result of ankylosis, wi_th

exagerated periapical inflammation, progressive vertical

bone loss, and extensive inflammatory and replacement

root resorption. Grewe and Felts (16) found, by study-

ing tritiated thymidine incorporation, that mouse teeth

replanted into their sockets exhibited further growth

and maturation. Teeth transplanted from one animal

to another, however, were all non-viable, and showed no

growth or maturation, many becoming exfoliated. Various

techniques have been used in an attempt to improve

transplantation successa Weinreb, et al (17) found

that if a portion of the accompanying alveolar bone in

autogenous transplants was implanted along with the

grafted tooth with the periodontal ligament intact,

root resorption would not occur. Contrary to these

findings, however, Luke and Boyne (18) have shown that

the transplantation of teeth with the surrounding perio­

dontal ligament and bone resulted in an extensive root

resorptive process. Costich, et al (19) replanted and

transplanted 120 hamster molars, finding that freezing

teeth at -70° C and storing them at -8° C for one to 66

days before replantation or transplantation led to an

overall 60% rate of successful retention for up to 89

days. Storage of teeth in culture medium at 37° C for

one to two days led to 77% success.

Transplantation of teeth from one animal to another

is complicated by immune reactions to foreign tissue.

Boyne (zo) reported that the rejection phenomenon after

tooth transplantation, although not of the same magnitude

as that elicited by other types of tissues, may be

evidenced by a chronic inflammatory infiltration of cells

8

surrounding the transplant and extending into the pulpal

tissue. Failure of the pulp to function as a dentin­

forming agent and to assist in the completion of the

structure of the tooth root, with fibrous encapsulation

and root resorption with replacement by osseous tissue

are also seen. The results of a study by Robinson and

Rowlands (21) in 1972 also show that teeth used in

transplantation are antigenic. Prior sensitization of

the recipient by skin grafting resulted in more frequent

loss of the tooth allografts and more intense lympho­

cytic infiltration around the graft beds. In a later

study (22), 1974, the same authors evaluated tooth allo­

grafts in Syrian hamsters, and found that while isolated

allogenic mineralized tooth surface, with the periodontal

ligament enzymatically removed, was not immunogenic

9

(did not serve as a primary response to secondary skin

grafts), isolated periodontal ligament was shown to evoke

an accelerated rejection of skin grafts, proving its

antigenicity. How the rejection phenomenon and the

inflammatory reaction usually associated with transplanted

teeth relate to the inflammatory resorption, ankylosis,

and too frequent failure of replanted avulsed teeth, is

a matter that deserves much more study. As LeCavalier

(23) stated, "many authors believe that the body treats

replanted teeth as a foreign protein and thus eventually

rejects them."

Several studies have been done.in the last twenty

years to determine the longevity of replanted avulsed

teeth, although many failed to isolate the individual

factors affecting success.

In 1959, Lenstrup and Skeiller (24) followed the

progress for several years of forty-six patients who

had traumatically avulsed teeth replanted using various

methods, and concluded that "the long-term prospects of

preserving a replanted tooth are unfavorable, since

root resorption results in most cases." Garber (25),

in 1965, stated that replanted teeth had an average

retention of five years, as reported by most clinicians.

Ingle (26) feels that the average life span of such

teeth is between five and ten years. Grossman (27),

in 1970, complained that papers on replantation claiming

success after only six to twelve months are not valid,

and followed 54 cases from various sources for up to

10

three yearsa Two thirds of the teeth remained in function

for two or more years. Kemp, et al (28), in a continuation

of Grossman's study including 71 cases, found that the

longer the teeth were replanted, the more likely that

root resorption would occur, while the teeth replanted

for the longest period had the fewest periapical rare­

factions. They concluded that replantation of avulsed

teeth is justified despite the fact that it is not usually

a permanent procedure. "Success" of a replanted tooth is

a relative term, and the success rates reported depend

greatly on the criteria on which the judgement is based.

Messing (29) used as his definition of success "fixation

of the tooth in its socket without residual inflammation,

.•. either by ankylosis or by regeneration and reattach-

11

ment of the periodontal ligamenc the latter mode obviously

preferred." Emmertsen, et al (9) regarded as successful

any implant that was firm in normal function and had

normal gingival attachments and no root radiolucencies.

Talim and Antia (30) followed up fourteen intentional

replants for one year and concluded that nine were

successful using the following criteria: The teeth must • perform masticatory function without discomfort, gingival

color, contour, texture, and sulcus depth must be normal,

and theremust be no radiographic evidence of resorption

of tooth or bone. Knight, et al (31) pointed out the

great difference between clinical and histologic criteria

for success, with the results of his work replanting

teeth in dogs. Seven of sixteen teeth were clinically

successful, showing stability, function, and absence of

inflammation in soft tissue. None of the sixteen teeth,

however, met their histologic criteria of success, ~hich

was defined as the absence of root resorption, abscess,

and cyst formation, reattachment of the epithelium at

the proper level, reformation of the periodontal ligament

12

without ankylosis, and reestablishment of the vitality

of the tooth. In practice, one certainly must be satisfied

with meeting clinical success criteria, but it should be

noted that it is not usually a normal histologic result.

The histologic mechanism of healing of the perio-

dontium surrounding replanted teeth has been studied

" extensively. Andreasen and Hjorting-Hansen (32) found that

the first six weeks are the most critical to the survival

of the implant, since this is the period of major pro­

gress in the healing of the periodontal membrane. Woehrle

(33) found that although there may be a "primary reattach-

ment" or a true healing of the severed periodontal tissue,

an extended or adverse extraoral course led to a "secondary

reattachment." This involved replacement of degenerating

periodontal tissues attached to the replanted tooth by

new ligament fibers provided by viable alveolar fragments.

The alveolar fragments also provided cellular elements

for the secretion of a new cementum matrix. Then, entrap-

ment of the regenerating fibers in the newly deposited

calcifying cementum provides a functional periodontium.

This secondary reattachment, according to Woehrle, is

dependent on the status of the supporting alveolar tissues,

the replant being passive, a substrate for cementum

deposition dictated by the extraoral history and the

periodontal tissues. Johansen, (34) after replanting

13

teeth immediately, found that true reattachment was an

unpredktable occurrence, and postulated that reattachment

took place in the vascular area of the periodontal mem-

brane without new formation of bone and cementum as a

prerequisite~ This healing by first intention was the

initial phase of reattachment of the extracted tooth,

and it took place without new formation of the entire

fiber apparatus across the periodontal membrane. By the

eleventh day the fibers and the bone along the original

alveolar wall were replaced by new fibers embedded in a

layer of new bone. Caffesse, et al (35) replanted teeth

in monkeys twenty minutes after extraction, and found

that a highly cellular periodontal membrane developed,

and although fibers reattached to reparative bone and

cementum, they seldom regained functional orientation.

Cervical~and apical root resorption was a universal

complication, but arrested areas of resorption often

showed repair by deposition of cementum. Massler (36),

in a clinical assessment of healing following tooth

replantation, stated that epithelial cuff reattachment

occurred at one week, periodontal ligament reattachment

in two to four weeks, and root resorption was evident

radiographically by six weeks. Nasjleti, et al (37)

agreed that a new junctional epithelium was established

(in monkeys) at seven days, while at the same time

.. connective tissue proliferation was at its peak, ?'\

starting mainly from the supro-crestal connective tissue

and the bone marrow spaces. The interface in the

periodontal ligament was undetectable histologically

by seven days. Large numbers of epithelial rests were

seen in the periodontal ligaments of the replanted teeth.

Loe and Waerhaug (38) hypothesized that the epithelial

rests of Malassez play a role in the maintenance of the

periodontal space in teeth replanted with a "vital"

periodontal membrane. Kaplan and Ward (10) stressed

the importance of the organizing blood clot in the repair

of the periodontal ligament when kept vital, the repair

being complete in one month. Hamner, et al (39) studying

replanted teeth in baboons, described a massive infil­

tration of lymphocytes and plasma cells in the healing It

periodontal membrane. Rockert and Ohman (40) found that

within one month after replantation, demineralized areas

were seen in cementum and dentin using microradiography.

These seemed to be areas of degenerative change and they

thought that the demineralization was caused by lack of

"membrane covering cementumc"

The location of the epithelial attachment was

unpredictable after replantation, according to Groper

and Bernick (41), but Deeb (42) feels that elimination

14

of periodontal disease by curettage of crevicular epithel­

ium and careful repositioning of gingival tissues is

important in replantation procedures in order to improve

a predictable reattachment.

Root resorption is such a common occurrence after

replantation that many authors have considered it normal

and unavoidableo Caffesse, et al (35) after following up

replanted teeth in monkeys for three to four years, con­

cluded that cervical and apical root resorption is a

universal complication after tooth reimplantation, and

that arrested areas of resorption will show repair by

deposition of cementum. Andreasen and HjBrting-Hansen

(43), however, described thDee separate and distinct types

of root resorption. The first and most desirable was

minor"surface resorption" that occurs in what they de­

scribed as normal healing, which is quickly repaired by

cementum deposition. The second was "replacement resorp­

tion," or progressive ankylosis with tooth structure

replaced by bone. ·The third type was referred to as

"inflammatory resorption," and was the most destructive

15

type, tooth structure rapidly becoming replaced by granu­

lation-type tissue. Within each type, Andreasen (44) later

distinguished between active, arrested, or repaired areas

of resorption when studied microscopically. He believed

that since it was observed that resorption, when present,

always started within one year after replantation, only

teeth with an observation period greater than one year would

be regarded as successful. (43)

16

Surface resorption was described in a histologic

study of replanted human teeth by Andreasen and Hjorting­

Hansen (32) as showing small superficial resorption cavities

in the cementum and outermost layers of the dentin. No

inflammatory reaction in the periodontal membrane was

seen, and most cavities showed repair with cementoid.

Barbikow, et gl (45) working with monkeys, described surface

resorption as becoming evident within two weeks after

replantation. Andreasen (46) postulated that these super­

ficial resorption lacunae may represent localized areas of

traumatic damage to the periodontal ligament or cementum,

and that it was self limiting, usually with spontaneous

repair. Normally, only the most severe of these are seen

radiographically, and clinically a normal percussion sound

is heard.

In a histometric study of periodontal healing in

rats by Andreasen, (47) an experimental injury with a bur

through the vestibular bone, periodontal ligament, and

superficial root surface of a mandibular molar was seen

to heal in three phases. Bone repair with formation of

an ankylosis occurred initially, followed by repair

of the periodontal ligament including removal of the

established ankylosis, with repair of the cementum

occurring last. In another study by the same author (48)

assessing periodontal healing after replantation of avulsed

17

human teeth, he described two distinct types of ankylosis.

The first he called a "transient replacement resorption,"

with radiographic signs of ankylosis and clinical lower-

ing of tooth mobility, both disappearing within several

weeks. This may be the same type of healing that he

described after the injury to the rats. The second type

of ankylosis, however, was a "permanent replacement re­

sorption," with lowered mobility values occurring by five

weeks, radiographic signs of resorption without radiolucency

of tooth replaced by bone not evident until eight weeks.

Andreasen and HjBrting-Hansen (32) described this histolo­

gically as showing cementum and bone being replaced by, and

in direct contact with, lamellar bone, with osteoblastic

activity often evident. Andreasen (46) hypothesized that

a blood clot in the periodontal ligament organized into

granulation tissue, and was replaced rapidly by bony

trabeculae uniting.the alveolar socket with the tooth.

Root resorption may or may not preceed ankylosis. The

tooth may be involved in the normal remodeling cycle of

the bone, gradually being replaced py bone. The same author

also stated that the replacement resorption was usually

first seen radiographically by three to four months

after replantation, usually starting in the apical one

third of the root. Often eruption was halted, and the

percussion sound was high-pitched. Barbikow (45) believed

that while replacement resorption was caused by devitalized

periodontal ligament tissue, inflammatory resorption was

caused by necrotic pulpal products.

Inflammatory resorption, as described by Andreasen

and HjBrting-Hansen (43), was often seen as early as

18

three to four weeks after replantation, and was radio­

graphically characterized by loss of root substance with

adjacent radiolucency in the bone. Histologically, the

same authors (32) described bowl-shaped areas of resorp­

tion of cementum and dentin, associated with inflammatory

changes of the adjacent periodontal tissue. The resorp­

tive areas were characterized by Howship's lacunae

containing multinucleated cells, and in the inflamed

periodontal tissue were seen intense concentrations of

polymorphonuclear leukocytes, lymphocytes, and plasma

cells, with proliferation of capillaries. Andreasen (46)

believed that small resorptive cavities in the root

surface may expose or open dentinal tubules. This may

allow necrotic tissue, toxic autolyzed pulp components,

or bacteria from a necrotic pulp or an inadequate root

canal filling to penetrate into the periodontal tissues,

causing an inflammatory reaction. Andreasen and HjBrting­

Hansen (32) carried this further, saying that inflammation

of the periodontal ligament from necrotic tissue in the

canal provoked a response which could result in complete

resorption of the root with no attempt at repair, as long

as the necrotic'pulp was present.

One of the multitude of variables affecting the

successful healing after tooth replantation is the

19

extent of damage to the teeth and supporting structures.

Andreasen (49) considered root fracture a contrain­

dication to replantation. According to Humphrey (50), the

maxillary anterior teeth are the teeth most often avulsed,

and the alveolar bone in this area is often displaced,

or even fractured. Woehrle (33) believed that the viable

alveolar fragments were the source of the new ligament

fibers and cells for new cementum secretion, so it was not

surprising that Andreasen and HjBrting-Hansen (43) found

that of nineteen cases of replantation with accompanying

alveolar bone fracture, all showed extensive resorption

and a poor long-term prognosis. McCagie (51), however,

reported a case where three teeth were replanted after

being out of the mouth for five days, with loss of most of

the buccal plate. Two and one-half years later, very little

resorption was evident. Lu (52) recommended replanting

teeth even adjacent to jaw fractures after soaking them in

benzalkonium chloride. He thought that root canal therapy

was not.necessary as long as the teeth had a "normal

appearance clinically," but that healing of a replanted

tooth normally occurred by ankylosis.

The stage of root development at the time of avulsion

has been shown to affect the course of healing after

replantation. Kaqueler and Massler (53), in a study

using dogs, found that replantation of mature teeth was

uniformly less successful than that of immature teeth,

when endodontic therapy was not done. Although the

extraoral time period was more important to the immature

teeth with open apices, the temperature and storage

20

medium variables were more important than the extraoral

period to mature teeth. Lenstrup and Skeiller (24) found

in studying forty-six patients with replanted teeth that

the younger the tooth, the more pronounced and progressive

was the resorption. Andreasen (46) found that inflam­

matory resorption was especially frequent in permanent

incisors with incomplete root formation, possibly because

of thin dentinal walls and wide dentinal tubules, through

which toxic pulpal products could more easily pass. The

pulps of the immature teeth, however, revascularized

more often than those of mature teeth. Massler (36)

said that mature teeth healed more slowly than immature

teeth after immediate replantation, but that the difference

between the two was small if replantation was delayed for

more than 24 hours. Andreasen and Hj8rting-Hansen (32)

found that a functional arrangement of the periodontal

fibers after replantation occurred in almost all of the

young teeth, except in those areas of the root surface

where active resorption and ankylosis were present.

In the mature teeth, the fibers were usually randomly

arranged or ran parallel to the root surface.

21

Probably the two most important factors affecting

the survival of replanted teeth are the amount of time

that an avulsed tooth is outside the socket and the

environment that it is kept in during that time. McElroy

(54) reported on a case where a thirteen year old boy

knocked out four maxillary anterior teeth, immediately

replanted them himself, and they functioned for 44 years

afterward. Kemp, et al (28) studying 71 avulsed teeth

replanted by many different clinicians, found that only

13.7% of the teeth were replanted within one hour after

avulsion, so usually time out of the socket is a major

factor. Andreasen and HjBrting-Hansen(43), after studying

110 replanted avulsed human teeth for from two months to

thirteen years, concluded that the degree of replacement

resorption was proportional to the extraoral time. Ninety

per cent of teeth replanted within 30 minutes showed no

resorption, while the vast majority of teeth replanted

90 minutes or more after loss showed extensive resorption.

A variable frequency of resorption was seen in those with

extraoral periods of from 31 to 90 minutes. Flanagan and

Myers (55) extracted and replanted hamster teeth after

variable time periods, with the teeth kept in sterile

saline, and found that teeth replanted immediately or

22

within 30 minutes showed a minimum of tissue inflammation,

while those kept out longer, especially up to six hours,

showed very poor results, osteomyelitis, pulp necrosis,

and root resorption occurring. Kaplan and Ward (10) felt

that the success rate was directly proportional to the

amount of viable periodontal ligament present. They con­

cluded that an excessive extraoral period produced

irreversible degenerative changes in the periodontal

ligament prior to replantation. The presence of this

layer of necrotic tissue, which requires removal by

phagocytosis, retarded or prevented reattachment. There

are several studies, however, that minimized time and

environmental factors. Lenstrup and Skeiller (24) studied

46 patients who had had avulsed teeth replanted and found

no correlation between the extraoral period or method

of preservation, and the degree or rate of resorption.

They found that root resorption resulted in most cases.

Since this study was reported in 1959, it is possible that

replantation methods found preferable today were not used

in these patients. Anderson, et al (56) felt that the

periodontal tissues can become reattached even after

six hours out of the mouth. This was, however, not

attachment by a normal periodontal ligament. Groper and

Bernick (41) replanted teeth in dogs after extraoral

times from zero to twenty-four hours, with the teeth

kept in sterile gauze. They concluded that no evidence

appeared to show that dry storage alone for a period of

two hours or more had any effect on the presence of a

functional periodontal ligament, at least during the

period of their study. Repair of resorbed areas along

the entire root surface took place regardless of extra­

oral time. The thirty day length of their study may

not have been long enough to make any broad generaliza­

tions. Cvek (57) studied 38 human luxated and replanted

teeth for 22 to 78 months, and found that all teeth

stored dry for one hour or more became ankylotic. If

the dry interval was short, less than fifteen minutes,

23

the further course was good. If the dry interval was

moderate, ankylosis was less if the tooth was stored in

isotonic saline for about 30 minutes before replantation.

Barbikow (45) found that there was no difference in healing

after replanting monkey teeth immediately than after

storage for fifteen minutes in saline. Loe and Waerhaug

(38), after replanting 58 teeth in monkeys and dogs,

found that teeth replanted with a vital periodontal

ligament always formed a normal periodontal ligament

without ankylosis. Teeth allowed to dry for a short time

ankylosed, with minor areas of normal periodontal ligament

attachment, while teeth with periodontal ligaments dried

for longer times never formed normal periodontal ligaments.

24

Kristerson, gt al (58) maintained the viability of perio­

dontal ligament cells of 21 teeth by the use of a transport

medium and tissue culture for four weeks. Four teeth

replanted after eleven weeks in this medium showed good

healing after five months. Nasjlete,· et 21 (59) found that

ten monkey teeth stored in a culture medium at 4° C for

seven days before replantation showed 100% success at one

year, while ten other teeth stored at -10° C for the same

time showed only 50% success. Jonck (60), however, stored

human teeth in isotonic saline at 4° C, and found active

resorption six weeks after replantation. Other teeth

which he stored in the patient's own blood (treated with

dextrose citrate to prevent coagulation) for three weeks

before replantation showed no signs of resorption after

two years.

The effects of various methods of direct manipulation

of the periodontal ligament on healing after replantation

has been discussed by many authors. Hammer, (61) in 1955,

believed that the life-span of a replanted tooth was

directly proportional to the area of the periodontal

ligament remaining attached to the tooth. Loe and Waerhaug

(38) found that teeth replanted in dogs and monkey~ after

removing the periodontal ligament by curettage never

regained their normal reattachment apparatus, but had the

periodontal space occupied by soft tissue, soon replaced

25

by bone, with ankylosis complete by 30 days. Bennett (62)

found that teeth replanted after scraping the periodontal

ligament formed a new periodontal membrane within two

or three months, but it was followed by complete bony

ankylosis and osseous rebuilding of the root. When the

ligament was not removed there was complete restitution

of a normal periodontal ligament within four to six weeks.

Hammer, et at (39) replanted teeth in baboons, discing

the distal root surface of the teeth, while leaving the

rest of the root surface alone. The mesial side main­

tained a good periodontal union twelve months after re­

plantation, with only focal microscopic resorption, while

the disced distal surface showed severe root resorption,

with a massive infiltration of lymphocytes and plasma

cells in the periodontal ligament. Sherman (63) replanted

incisors in dogs after performing root canal therapy.

More extensive root resorption and ankylosis were observed

on the teeth replanted after scraping the root surface

and wrapping with resorbable surgical sponge as a perio­

dontal ligament substitute than those replanted with the

periodontal ligament unmanipulated. Ogus (64) described

a technique which involved casting and cementing a vitallium

thimble implant with a rough external surface over the

prepared root surface before replanting teeth, in an

effort to prevent root resorption. No actual clinical

cases were reported. Keller, et al (65) in an effort to

26

stimulate fibrotic attachment of replanted monkey teeth

to the socket, adapted venous segments over the roots of

teeth prior to replantation. Increased sulcus depth, root

resorption, and ankylosis were seen in the experimental

teeth compared to control teeth. Natkin (66), discussing

the value of scraping the periodontal ligament before

replantation, stressed the importance of whether or not

the ligament alone is removed, or whether the cementum is

also removed, exposing dentin. Morris (14), found that

after surgical detachment of periodontal tissues, healing

was normal against untouched or lightly curetted cementum,

but healing did not occur against the bare dentin of teeth

with non-vital pulps, including those with previous root

canal therapy. Baurer, et al (67) was able to remove the

periodontal ligament enzymatically from extracted teeth

in as little as fifteen minutes, without observable damage

to the cementum. Huard, et gl (68) using rhesus monkeys,

cultured periodontal ligament fibroblasts on enzymatically

debrided root surfaces, establishing a network of viable

fibers, and replanted one of these teeth in a monkey.

The tooth was reextracted seven months later, and a normal

looking periodontal ligament was seen with no visible

areas of resorption.

The advisability of apicoectomy before replantation

has been debated. Harris (69) advised cutting off the root

apex, cleaning out the root canal, and leaving the

lingual access open to avoid f-luid pressure in the

periapical area. If root end resorption occurred later,

he recommended treating it by surgical exposure and

"shaving" the root end down to "fresh" tooth structure.

Anderson, ~ al (56) thought that cutting off the root

end in older teeth promoted repair by secondary cementum

and reattachment of the periodontal ligament in this

area, and Massler (36) advocated "snipping off the root

tip" if the tooth resists replacement in its former

locus. Bennett (62) disagreed with these procedures.

He believed that since it has been suggested that resorp­

tion begins where small pieces of cementum are torn from

the root during extraction, it would follow that apico­

ectomy should not be performed.

27

Although there is almost complete agreement in the

literature that replanted teeth should be splinted, there

is little agreement as to the type and duration of splint­

ing. A most unusual splint was one reported by Serrano

(70), where a horizontal hole was drilled through the

alveolar bone and root of the replanted tooth, through

which was driven a "retention rod" of calf's bone. Others

were more conventional. Pearson and Nicolazzo (71) de­

scribed an arch bar wiring technique, while Barbikow (5)

recommended splinting by full arch coverage with an

appliance to open the bite from two to four m~llimeters.

Biven, et al (72) suggested processed acrylic buccal and

lingual splints, which~ wired together through the

interproximals. Jenner (73) recommended a ligature

wire splint covered with cold-cure acrylic, while

Rand (74) described an linusual technique of suturing

28

through the buccal and lingual periosteum, with the suture

running over the incisal edge between the mammelons.

Humphrey (50) splinted anterior teeth by soldering

together interproximally either stainless steel crowns

or orthodontic bands. McEvoy and Mink (75) advocated

acid etching the labial surfaces of the teeth, then apply­

ing a 3 mm. strip of acrylic resin across the labial

surfaces and interproximals. Heiman, et ~ (76) described

a splint attaching an arch wire to the labial surfaces of

the teeth by means of an adhesive composite system. Hovland

and Gutmann (77) cemented direct-bonded, mesh-backed

orthodontic brackets to the teeth, and attached an arch

wire with elastic ligatures, and Berman and Buch (78)

covered similar direct-bonded brackets with a band of

acrylic.

Although Johansen (34) found when replanting guinea

pig teeth that splinting or not splinting showed no

difference in healing, splinting of avulsed human teeth

aft~r replantation has been almost universally accepted.

Barbikow (5) thought that 30 day immobilization was needed,

29

Pearson and Nicolazzo (71) recommended splinting for six

to eight weeks, Hargreaves and Craig (79) for eight to

twelve weeks, and Henning (80) advised "at least three

months." Andreasen (44) has published the only objective

research into this area, replanting teeth in 21 monkeys,

splinting for six weeks, two weeks, or no splint at all.

The monkeys were sacrificed at eight weeks, and although

teeth that were out for 120 minutes showed extensive

ankylosis irrespective of splinting method, teeth that

were out for eighteen minutes showed significantly less

frequency and extent of replacement resorption when not

splinted compared to the splinted teeth. Andreasen (81)

at the present time recommends splinting replanted teeth

for one week only.

Antibiotic coverage has been advised (71), and

in cases of severe tissue injury is probably warranted

but Massler (82) and Andreasen and HjBrting-Hansen (43)

have both shown experimentally that systemic antibiotic

administration did not significantly affect the rate

of healing of the periodontal tissues.

Disinfection of root surfaces before replantation

has been advised by some authors. Loe and Waerhaug (38)

washed roots in 1% phenyl mercuric acetate, Messing (29)

soaked teeth in chlorhexidine diacetate solution for

five minutes, and Lu (52) soaked them in benzalkonium

chloride. Massler (82), however, found that applying

caustic drugs such as phenol or silver nitrate in an

attempt to disinfect the tooth increased the rate and

extent of root resorption. Andreasen (49) concurred,

saying that attempts to sterilize the tooth surface may

damage or destroy vital periodontal tissue and cementum.

30

Other chemicaltreatments of avulsed teeth beside

germicides have been used in an attempt to improve

healing. Fluorides have been the most extensively tested.

Schulman, et al (83) soaked teeth from monkeys in sodium

fluoride solution before replantation and found mixed

results, with some apparent lessening of resorption of

the fluoride-treated teeth. Bjorvatn and Massler (84)

soaked rat teeth in 10% stannous fluoride solution for

five minutes before replantation, and found increased

resorption. Dilution to a 1% solution showed an improve­

ment of root resorption over control teeth, although

not totally preventing it. Bjorvatn and Weiss (85)

found that a 2% solution of sodium fluoride clearly

decreased root resorption in replanted rat molars.

Colletti (86) described a "root incision technique,"

where grooves were cut in the root exposing the canals

which were then filled with amalgam, and these teeth

were soaked in a 1 O% stannous fluoride solution for two

minutes. He claimed a 94% success rate in human teeth,

although he accepted ankylosis as an acceptable result.

31

In.another study Schulman, et al (83) found that after

tooth immersion in fluoride and replantation, the fluoride

vas taken up significantly into the bone of the socket wall.

White (87), in 1975, related a case where teeth traumatic­

ally avulsed were replanted after lying at the bottom

of a swimming pool for 24 hours. Healing was good, and

the author thought that since both were halogens, the

effect of chlorine may have been similar to that reported

by fluoride. Robinson and Shapiro (88) soaked hamster

molars in a diphosphonate solution before transplantation,

but found no difference in healing compared to control

teeth. Huebsch (89) treated root surfaces of dog teeth

with methyl-2-cyanoacrylate adhesive before replantation,

but the teeth were all exfoliated within fourteen to

sixty days. Nordenram, ~ al (90) superficially deminer­

alized roots of monkey teeth in hydrochloric acid, re­

planted teeth, and.found that the demineralizing treat­

ment caused an accelerated resorption and ankylosis of

the teeth. Bjorvatn and Weiss (85) found that soaking

roots in tetracyclines before replantation produced a

marked increase in alveolar bone growth, so that roots

so treated became quickly ankylosed. Fong and Berger

(91), attempting to reduce the antigenicity of tooth

transplants, irradiated the teeth with high doses of x­

radiation, but observation of the transplants showed that

the radiation destroyed the viable tissues of the

autograft,.so that poor healing and no further root

development resulted.

~~ny studies have been undertaken to determine the

effect of endodontic therapy on replanted teeth. Some

authors felt it preferable to replant without pulp

therapy. In 1929, Skillen and Lundquist (7) replanted

teeth in dogs, and found that "the (endodontically)

treated tooth suffered much more extensively through

resorption than the untreated, fusion of bone and

32

cementum also occurring in the former." The exact method

of endodontic treatment was not mentioned, nor was it

clear whether or not the extraoral times were equal.

Various studies have shown that sometimes pulp vitality

can be maintained to some extent. Costich, gt al (92)

immediately replanted 29 hamster molars immediately after

extraction. At three months, most had vital tissue in

the canals, some with osteodentin formation, .but almost

one half also showed ankylosis. Sorg (93) replanted

twenty hamster second molars with developed apices

within five minutes after extraction. Sixteen of twenty

teeth were retained until the 34 to 63 day sacrifice time.

Nine of these sixteen showed regenerated nerves within

the pulp, three of these pulps being histologically

normal, six pulps showing normal tissue with varying

amounts of osteoid material. Morrison (94) reported a case

33

where a central incisor with an undeveloped apex was

replanted within 30 minutes of traumatic avulsion. Three

weeks later the tooth responded to thermal and electric

vitality tests, and two years later a normal completely

developed root apex was seen on x-ray examination. Ten

years later the pulp chamber was completely filled

in radiographically, but the periapex and periodontal

ligament appeared normal. Henning (80) felt that it was

probable that the time taken in performing root filling

before replantation led to damage to the root surface

because of increased extraoral time, which may outweigh

the benefits of pulp removal. Rothchild, et al (95)

replanted teeth in dogs, and concluded that there appeared

to be little difference, if any, between endodontic and

non-endodontic replants with respect to ankylosis and

bone deposition (at 30 days.) This was not in agreement

with the earlier study by Knight, ~ al (31), also using

dogs. Knight found that although all teeth showed mild

to severe diffuse resorption, localized cervical resorp­

tion was much worse in the untreated teeth. Ankylosis

occurred with equal frequency in treated and untreated

teeth, but general tissue response was better in t~e

treated teeth. They recommended that replanted teeth

have root canal therapy done as soon as possible. Barbikow

(45) replanted central incisors in monkeys with and with­

out root canal therapy, with an average time extraoral of

34

fifteen minutes. They found no difference in healing for

up to eight weeks, other than the presence of periapical

abscesses in the non-treated teeth. Andreasen and HjBrting

Hansen (43) followed up 110 replanted human teeth. They

concluded that if a replanted tooth was not endodontically

treated and the pulp became necrotic, toxic products from

the pulp could destroy the periodontal membrane and

cementum via the dentinal tubules. This would cause poor

healing and inflammatory resorption, usually leading to

loss of these teeth in from two to ten months.

Often the stage of root development has been used as

a factor in deciding whether to replant and hope for pulp

revitalization, or to perform endodontic therapy. Anderson,

et al (56) found that the size of the opening of the apical

foramen was important to pulpal survival. Andreasen and

HjBrting-Hansen (43) reported that seven of thirteen

human teeth with open apices replanted without endodontic

therapy showed pulp survival, with gradual obliteration

of the pulp chamber. Six teeth showed pulp necrosis, five

of these with extensive rapid inflammatory resorption.

Andreasen (46) found that teeth with open apices may

revascularize if out of the socket for less than 30

minutes, with some chance of revascularization up to two

hours. Most of these teeth showed arrested root develop­

ment and pulp canal obliteration with osteoid or bone.

35

Monsour (96) replanted anterior teeth with open apices

in eight dogs. Most teeth showed the entire pulp chamber

filled with granulation tissue leading to "osteo-dentin"

deposition by cells differentiated from the fibrous

replacement tissues. He felt that vital replantation

was superior to root canal therapy if done immediately II

and with open apices. Ohman (97 & 98) studied teeth that

were replanted immediately and reextracted at various

later times, finding that regenerating nerve fibers were

evident at one month. This was consistant with vital pulp

test responses that were seen two months after replantation

in 33 of 37 teeth tested. He said that a better indica-

tion of vitality was the reduction in the size of the pulp

chamber radiographically. Smith (99) reported a case

where a 26 year old man replanted his own tooth immediate-

ly after it was totally avulsed into his mouth. Although

the apex was fully developed, it remained in function for

25 years with calcific degeneration of the pulp, but no

root resorption or apical rarefaction was evident radio-

graphically. In spite of an isolated case like this,

Whiteacre and Edwards (100) said that pulp necrosis occurred

in over 80% of replanted teeth with closed apices, and

root canal therapy should be instituted as soon as this

occurs.

36

The length of time that an avulsed tooth is out of

the socket, and thus the degree of pulp tissue breakdown,

should be of prime importance in deciding whether or not

to institute immediate endodontic therapy. Heithersay

(101) normally recommended replanting the tooth

immediately, then commencing root canal therapy within

ten days, unless the tooth was out longer than two hours,

in which case endodontic therapy can be carried out first.

Deeb (42) said to perform endodontics prior to replanta­

tion, unless the tooth was out less than one hour, in

which case endodontics should be delayed three to four

weeks to evaluate pulpal healing. Andreasen and HjBrting­

Hansen (43) believed thatpulp removal and endodontic

therapy should be performed as soon as possible to prevent

inflammatory resorption from pulp breakdown products, but

not at the expense of increasing the extraoral time. The

same authors (32) in another study found that pulp necrosis

usually occurred between two and seven weeks after replanta­

tion, if at all, so they recommended immediate replantation

with endodontic therapy done within two weeks afterward.

Many materials and methods have been recommended for

performing root canal therapy on avulsed teeth. Bennett

(62) believed that the material used for the root filling

does not appear to influence the reattachment, provided

there-is an adequate apical seal. Pulp extiration alone

is not advised, as Woehrle (33) found that this caused

abscess formation in replanted teeth, while complete

endodontic therapy showed minimum periapical pathosis.

Andreasen and HjBrting-Hansen (32) recommended gutta­

percha and sealer as a root canal filling, while Deeb

37

(42) and Messing (29) advised performing an apicoectomy

and reverse filling with amalgam. Harndt and Hoefig (102)

described the use of a chromium-vanadium steel endodontic

implant to aid in the retention of a replanted avulsed

tooth. Marosky (103) recommended a vitallium post as a

filling material, as it could be easily removed if severe

resorption occurred necessitating extraction, with calcium

hydroxide as a sealer, as it is resorbable and may retard

resorption. Recently calcium hydroxide has itself been

shown to have an effect on root resorption. In 1973

McKinley (104) described a case where external root resorp­

tion following avulsion and replantation of a central

incisor was arrested by placement of a calcium hydroxide

paste in the root canal. The tooth was later filled

with gutta-percha and sealer.

Calcium hydroxide has had a multitude of uses in

dentistry, beginning in 1930 when Hermann (105) introduced

it as calxyl for pulp capping, showing the ability of the

pulp to protect itself through formation of a dentin bridge.

38

Zander (106), in 1939, described pulp healing after treat­

ment of pulp exposures with pure calcium hydroxide. Later,

in 1949, Glass and Zander (107) found that calcium hydrox­

ide acts as a stimulus for the conversion of undifferent­

iated mesenchymal cells of the pulp to form a new odonto­

blastic layer after pulp injury. When calcium hydroxide

was used as a base, MjBr (108), in 1967, found that sound

dentin showed increased density through intratubular

secondary mineralization. Avery (109) found that calcium

hydroxide would induce reparative dentin underlying a

cavity much more readily than under an exposure. Heys ~ al

(110) showed that calcium hydroxide, when placed in cavities

of moderate depth, produced at three days a moderate pulpal

inflammatory response. By five weeks a decrease in inflam­

mation and the formation of repairative dentin was seen,

with sclerosis of dentinal tubules. Macchetti and Toledo

(Ill) used tetracycline to study secondary mineralization

of healthy dentin under calcium hydroxide bases, and found

increased mineralization in the dentin below the base,

and at the dentinopulpal boundry. The time during which

calcium hydroxide acted on the dentin was relatively short,

reaching its maximum on the second day after treatment,

with the effects disappearing completely by the fifth

day. Eidelman, et al (112) placed calcium hydroxide over

the deepest one millimete~ of remaining carious dentin

(indirect pulp cap) after deep excavations. They found

a significant increase in phosphorous content when the

remaining dentin was checked after two to twelve weeks,

indicating that a remineralization of the carious dentin

occurred. Spedding, ~ al (113) found that 60% of pulp

caps in monkeys were successful when calcium hydroxide

was used, while formocresol showed 70% success and was

39

judged superior as a pulp capping agent .. Kozlov and

Massler (114), however, found that pulp caps in rat molars

with calcium hydroxide produced a good repairative reaction,

with a small zone of inflammation, well encapsulated.

Under this a wide bridge of repairative dentin was formed

centrally and laterally to bridge the site of amputation,

with normal, relatively uninflamed, pulp beneath.

Krakow, gt gl {115) and Moodnik (116) recommended

vital calcium hydroxide pulpotomy for immature teeth with

damaged pulps, in order to allow for continued apical

development. While Moodnik advised that root canal

therapy be performed after apical closure, Krakow said

that it was not necessary unless calcification of the canal

was seen on recall examination. Via (117) studied 800

cases of calcium hydroxide pulpotomies, and found only

31.1% success, most failures because of internal re---

sorption. SchrBder and Granath (118) stressed the

importance of the calcium hydroxide being in intimate

40

contact with vital pulp tissue, because otherwise an

eosinophilic calcium-hydroxide-fixed extra-pulpal blood

clot was formed betweeh the two. This could give rise

to chronic granulation tissue and internal dentin resorp­

tion. SchrBder (119), and SchrBder and Granath (120)

found, after experimental pulpotomy, a layer of necrosis

immediately beneath the calcium hydroxide which irritated

the underlying pulp to respond with hard tissue formation.

They believed that the high pH of the calcium hydroxide

was responsible for the tissue changes.

In 1961, Nygaard-Ostby (121) described apical closure

by hard tissue deposition of teeth with open immature

apices and necrotic pulps. He accomplished this by

placing a short root canal filling after purposely lacer­

ating the periapical tissues to produce a blood clot,

which organized into cementum-like tissue. Kaiser (122)

in 1964 introduced the idea of treating these teeth with

a paste made by mixing calcium hydroxide with camphorated

parachlorophenol, which produced a bridging over the apex

allowing proper obliteration of the canal and eliminating

the need for surgery. Frank (123) in 1966 expanded on

Kaiser 9 s treatment, outlining a step-by-step proced~re

for calcium hydroxide and camphorated parachlorophenol

treatment of open-apex permanent teeth with necrotic pulps.

Michanowicz and Michanowicz (124) in 1967 recommended

placing a layer of calcium hydroxide at the end of a

canal with an open apex, and condensing gutta-percha and

sealer into the canal. Frank (125) in 1967 explained

that calcium hydroxide was used for the apexification

technique because it was simple and inexpensive, but

that it was the removal of infection, not the calcium

41

hydroxide, that allowed Hertwig's sheath to resume its

function of apical closure. Steiner, ~ al (126) thought

that introduction of the calcium hydroxide paste after II

stimulating apical bleeding (Nygaard-Ostby) may be the

most favorable condition for stimulating closure of the

apex. Van Hassell and Natkin (127) in 1970 reported

calcium hydroxide-induced root end closure of immature

molar teeth with necrotic pulps. In 1971 Dylewski (128)

studied calcium hydroxide apexification of immature monkey

incisors, and found that instead of a continuation of

normal root development, the calcium hydroxide induced a

repair process in the connective tissue of the apical

area. That same year Steiner and Van Hassell (129) found

that the calcific root end closure that formed when calcium

hydroxide was used satisfied the usual criteria for identi­

fication as cementum. Torneck and Smith (130) and Torneck,

gt al (131, 132, 133) studied the effects of various

procedures on the apical development of immature monkey

teeth. Some degree of root growth and foraminal closure

were seen after pulpectomy with and without coronal seal,

and with and without canal disinfection and medication.

The use of a calcium hydroxide treatment paste, however,

increased the predictability and amount of hard tissue

formation over any of the other treatments.

Other authors have questioned the value and effect

of the calcium hydroxide in apexification. Ham, et al

(134) found that periapical healing and calcified tissue

42

formation could occur in monkeys with either short gutta-

percha or calcium hydroxide paste fillings. Roberts and

Brilliant (135) in 1975 found that tricalcium phosphate

was as effective as calcium hydroxide in inducing apical

closure in human immature pulpless teeth. They concluded

that it was not the highly alkaline pH of calcium hydrox­

ide (11.8) that induced closure, because the pH of the

tricalcium phosphate was only 8.6. In 1977 England and

Best (136) extripated the pulps in 40 permanent premolars

with immature apices in seve~ young dogs, leaving half

of the teeth open to the oral environment and sealing the

other half with a temporary cement. Without the use of

any drugs in the canals, by seven to eleven weeks 85.5%

of the open teeth and 50% of those that were closed -

showed complete apical closure. It was concluded that

drugs such as calcium hydroxide were not necessary to stim-

ulate apical closure in dogs.

Calcium hydroxide pastes also have been evaluated

as a root canal filling material in teeth with mature

apices. Matsumiya and Kitamura (137) found that filling

the root canals with a paste made of calcium hydroxide

43

and sterile water had the effect of accelerating the

natural healing functions in the periapical tissues of

dogs. They felt that this was due in part to an anti­

microbial effect of the calcium hydroxide in the apical

tissues. Holland (138) and Martin and Crabb (139) reported

that calcium hydroxide was an excellent root canal filling

material, showing periapical healing by hard tissue for­

mation, throughaprocess similar to the pulp healing when

the same material is used there. Stromberg (140), however,

showed no statistically significantdifferences in healing

between teeth filled with calcium hydroxide, dibasic

calcium phosphate (pH7) and gutta- percha with chloro­

form-resin. Weinstein and Goldman (141) found that no

apical bridging was observed after mature monkey teeth were

debrided and filled with calcium hydroxide paste. They

concluded that the metabolism of teeth with mature apices

was quite different from teeth with immature apices.

Calcium hydroxide has been shown by Frank and Weine

(142) to effect the periodontal healing of a perforative

defect of internal resorption when placed in the debrided

canal. A later permanent root canal filling may then be

placed against a matrix of normal periodontal tissues.

44

Frank (143) further applied this technique to aid in the

repair of mechanical performations as the result of a

misdirected bur. Stewart (144) also demonstrated the

healing of internal or external root resorptive defects

after placement of a calcium hydroxide paste into the

canal. He suggested that metacresylacetate was less

irritating and gave more rapid healing with calcium

hydroxide than did the camphorated parachlorophenol used

by the previous two authors quoted. Sinai (145) in 1977

suggested that the induction of calcification external to

the tooth by calcium hydroxide is basically the same

process whether resorptive perforations or open apices

are the sites of calcific repair.

Andreasen (46) in 1971 suggested that endodontic

therapy may arrest inflammatory resorption in replanted

teeth by eliminating toxic degenerating pulpal products.

He recommended calcium hydroxide as the root canal filling

material in immature teetho Nine out of ten cases treated

with calcium hydroxide showed new periodontal ligament

formation and arrest of resorption. In five cases the

apical foramen sealed withhardtissue or completed root

formation. The same author (49) recommended convenrional

root canal therapy with gutta-percha and sealer for

mature replanted teeth showing inflammatory root resorp- .

tion. In some cases he thought that it would lead to an

arrest of the resorptive process. Cvek (146, 147)

found that treatment of replanted avulsed human incisors

showing external root resorption with calcium hydroxide

or gutta-percha and sealer showed the same results. 98%

of the for~and 94% of the latter showed arrest of pre­

existing external root resorption after treatment. He

felt that the high frequency of success in both groups

suggested that the removal of necrotic pulp tissue was

45

the decisive factor in the healingof external root resorp­

tion of the inflammatory or non-ankylosing type. In 1976

Burke (148) described a clinical case where external in­

flammatory root resorption was arrested in a replanted

tooth after filling of the canal with a calcium hydroxide

paste, with the development of a radiographically normal

periodontal ligament. A thorough histologic study has

not been reported investigating the value of the placement

of calcium hydroxide paste into the root canal at the time

of replantation, or the subsequent effect on root resorp­

tion.

Vital stains or dyes have been used in various

studies as markers to study the apposition and resorption

of bone, cementum, and dentiTh Hoyte (149) described the use

of alizarin red for this purpose, and Frost (150) the use

of tetracycline, which can be seen under fluorescent

microscopic examination. Goland and Grand (151) found

that Procion dyes, when given intravenously, permanently

46

marked incremental lines and zones of growth in teeth and

bone. The markers persisted during processing and decal­

cification of the specimins. Prescott, et al (152) found

that Procion Brilliant Red H-8BS was the most efficient

marker of the Procion dyes, and could be seen under both

ultraviolet light and light microscopy, even in decalcified

paraffin sections cut at 7~ • This same dye was used by

Sherman (63) in 1968 to study resorption of teeth after

replantation, and by Ham, ~ al (134) in 1972 to s~udy

apexification. Binnie and Mitchell (153) used both tetra­

cycline and Procion H-8BS to study induced calcification in

rat connective tissues, and Reames, et al (154) used the

Procion dye to label new bone overlying submerged retained

roots.

CHAPTER III

MATERIALS AND METHODS

Six healthy young adult beagle dogs, of inter­

minate age, randomly selected, three male and three

female, each weighing between 9.9 and twelve kilograms

were used in this study. The animals were individually

caged and maintained on a diet of standard laboratory·

meal and water ad libitum. All were radiographed

preoperatively to ensure normal anterior tooth anatomy

with complete apical development, and were examined

to determine that periodontal disease was either not

present or was limited to marginal gingivitis. All

radiographs in this study were taken using standard

bisecting angle radiographic technique, with a portable

hand held x-ray generator giving 60 K.V.P. at 20 mili­

amperes at 0.4 second exposure time. Kodak (a) peri­

apical ultra-speed film, size two, was held by a spring

type mouth-prop, with the x-ray source-to-film distance

kept close to twenty centimeters. Radiographs were

developed in a portable light-tight developing box in

Insta-neg (b) rapid developing solution for twenty seconds,

a Eastman Kodak Company, Rochester, New York.

b Microcopy, Culver City, California.

47

fixed in Insta-fix (b) concentrated fixer for forty

seconds, and washed in running water for five minutes.

Each suitable animal was premedicated with an

intramuscular injection of 1 cc. of Innovar (c) per

10 kilograms of body weight, the active ingredients

being fentanyl citrate 0.4 mg./ml. and droperidol

20 mg./ml., to sedate the animals and make them more

48

manageable, and also with a subcutane(j)US injection of

1.5 cc. of Atrosed (d) per 10 ~ilograms body weight,

active ingredient atropine sulfate 0.5 mg./ml., to limit

salivary flow. When the desired sedative effect was

reached, a foreleg was shaved, swabbed with alcohol,

the large anterior vein located, and an intravenous

injection of sodium pentabarbital (e) 65 mg./ml., an

intermediate acting barbiturate, was given to effect

(approximately 4 cc./10kg.,) as determined by the loss

of pedal reflex and the passage through the stage of

excitement into one of slow, steady resperation. When

the proper level of anesthesia was reached, the left

and right maxillary second incisors were extracted, . using sterile elevators and forceps, as atraumatically

and aseptically as possible, and held in sterile,

c Pitman-Moore, Inc. Washington Crossing, New Jersey.

d Burns-Biotec Laboratories Division, Chromalloy Pharmaceutical, Inc., Oakland, California.

e W.A. Butler Company, Columbus, Ohio.

dry, gauze during endodontic therapy, to allow the

periodontal ligament to dry, and serve as a controlled

stimulus for root resorption in experimental and control

teeth equally. In both left and right incisors lingual

access cavities were prepared to the pulp with a sterile

bur, and a number fifteen K-type endodontic file was

inserted until the tip could be seen through the apex,

sometimes easily accomplished, and sometimes requiring

some degree of force due to the multiple small foramina

common to dog root apices. The length of the files

were adjusted, and the canals were filed, using frequent

irrigation with 5.25% sodium hypochlorite solution, to

approximately a number forty file, one millimeter short

of the apex, and subsequently step-flared (1) several

sizes larger. Care was taken that the canal irrigant

49

not touch the external root surface. One of the incisors,

alternating left and right side on every other dog, was

immediately filled with laterally condensed gutta-percha

(f) and Procosol (g) non-staining root canal sealer,

while the contralateral tooth was filled with calcium

hydroxide powder and barium sulfate powder (for radio­

opacity) in a proportion of 6al, mixed to a thick paste

with camphorated monoparachlorophenol, and vertically

condensed to the apex with hand pluggers. The access

f Premier Dental Products Co., Philadelphia, Pennsylvania g Proco-sol Chemical Co., Inc., W. Conshohocken, PA

cavities were sealed with amalgam, and each tooth was

slowly but firmly replanted into its socket after being

held in dry sterile gauze for exactly sixty minutes

extraoral time. The periodontal ligament tissues on

the root surfaces were disturbed minimally during

treatment (other than allowing them to dry out,) and

50

the sockets were not curetted, but were flushed with

sterile saline, so as to loosen the blood clot but not

to remove periodontal ligament tissue on the socket wall.

Then the mandibular second incisors were extracted,

treated identically to the maxillary teeth, but filed

to one instrument size smaller apically due to the

smaller size of the canals, and each tooth was replanted

also in sixty minutes after its extraction. The labial

enamel of the six incisors in each arch was etched with

a phosphoric acid solution for one minute, great care

being taken not to let the etching solution touch the

gingival tissues, washed with a gauze pad soaked with

water, and air dried. Each replanted tooth, and the

tooth on either side of it, were notched on the labial

surface with a bur, wrapped with orthodontic ligature

wire in a tightly twisted figure-eight fashion, and the

labial surfaces of the teeth and wire were covered with

an orthodontic adhesive resin (h) for stabilization.

h Ortho International Services, Inc., Wilmington, Delaware

Postoperative radiographs were taken, and the animal

was placed back in its cage and given its normal diet

and water ~ libitum. Each animal appeared normal and

healthy by the first postoperative day.

Thirty days after the replantation procedure each

dog again was sedated with the same intramuscular dosage

of Innovar, and anesthetized lightly with intravenous

sodium pentobarbital. The splints were removed with a

scaler if still present, and the teeth were checked for

mobility and periodontal condition, specifically pocket

51

depth and gingival inflammation. Radiographs were taken,

and each dog received an intraperitoneal injection of the

vital dye Procion Red H-8B (i), 200 mg./kg. body weight,

in sterile saline to make 10 cc. of solution.

Sixty days postoperative each dog was sedated,

anesthetized, radiographed, and the teeth examined for

mobility and periodontal condition.

At ninety days postoperative time, each dog was

sedated with Innovar, anesthetized with pentobarbital,

radiographed, and examined for tooth mobility and perio­

dontal condition. It was then sacrificed by giving an

intravenous injection of 10 cc. of Bueuthenasia-D (j),

i Polysciences, Inc., Warrington, Pennsylvania.

j Burns-Biotec Laboratories Divsion, Chromalloy Pharmaceutical, Inc., Oakland, California.

a highly toxic parenteral solution of sodium pento-

barbital 195 mg./ml., and phenytoin sodium 25 mg./ml.,

specifically designed for rapid and painless euthenasia

of animals. Cessation of vital signs occurred usually

within ten seconds after injection of the drug. The

52

soft tissue surrounding the anterior maxilla and mandible

was quickly and carefully dissected free, and the an-

terior teeth with the surrounding bone was cut free

with an electric bone saw, and immediately placed in

10% neutral buffered formalin for fixation. The labial

and lingual plates of cortical bone were thinned and

opened in areas adjacent to the teeth to be studied to

allow for better fixation, and the formalin solutions

were changed every 24 hours for the first few days. The

specimins remained in the formalin for at least two weeks.

Subsequent to fixation, the jaws-were decalcified

for four to five weeks in a solution made up of equal

parts of solutions of 50% formic acid and 20% sodium

citrate, until radiolucent radiographically and of a

rubbery consistancy, when they were cut with a razor

blade into blocks of bone containing the individual

replanted teeth. A tooth which was not replanted was

included from each animal as a control. The individual

blocks were decalfified for several days to allow better

penetration. ~h individual tooth-bone block was then

cut into three segments, apical, middle, and cervical,

53

which were dehydrated in increasing concentrations of

alcohol and embedded in paraffin. Seven micron sections

were cut from the apical end of each segment, seven slides

with from ten to sixteen sections per slide from each

tooth segment. Of these seven slides, the first, fourth,

and seventh slides were stained with hematoxylin and eosin,

while the other four slides were left unstained and mounted

for examination by fluorescent microscopy or for possible

future special staining.

The radiographs of each pair of teeth were mounted

in plastic mounts, in the sequence of preoperative,

immediate postoperative, thirty day, sixty day, and ninety

day, so that the radiographic progression of healing and/or

pathosis could easily be determined.

CHAPTER IV

RESULTS

The operative procedures and postoperative course

of healing were accomplished quite smoothly. The only

problem encountered during the experimental replantation

was the difficulty of extraction of the mandibular inci­

sors of the dog. Because of the combination of very resil­

iant periodontal ligaments and thin roots of these teeth,

roots were fractured in dogs one and five, in spite of

extremely careful extraction technique. This necessi-

tated surgical extraction of the apical segments, and

resulted in four less teeth being used in the study than

originally planned, giving a total of twenty teeth extracted

and successfully replanted. The dogs seemed to suffer no

ill effects from the procedure after the first day, and

all animals appeared healthy throughout the study, with

no serious weight loss seen. The splints were well tol­

erated and functioned well, most lasting until the 30 day

evaluation when they were removed. All replantated teeth

remained in the socketthroughout the study, with the ex­

ception of three teeth in dog number four, which were

exfoliated due to severe inflammatory root resorption, two

before 30 days and one between 30 and 60 days.

The vital dye which was injected intraperitnneally at

30 days seemed to cause no ill effects on the health of

the animals, but one particular side effect was noted.

54

55

The sclera of the eye, the gingiva and lips, and the ab­

dominal skin were all stained a bright red color, which

persisted throughout the study. Apparently collagen was

stained by the dye as well as bone.

After sacrifice and histologic preparation of the

specimens, a systematic microscopic examination was made

of the histologic sections, which had been assigned a

coded numbering system. This allowed evaluation of histo­

logic criteria without knowledge of or bias towards the

filling material used. It was difficult to visually dif­

ferentiate between filling materials microscopically, be­

cause much of it was lost during processing and both the

calcium hydroxide and gutta-percha appeared as an amorphous,

granular mass when present. Thirty microscopic cross­

sections were examined from each tooth segment (apical,

middle, and cervical thirds.) Each section was examined

and graded in each of five categories: normal periodontal

ligament, surface resorption with a regenerated periodon­

tal ligament, replacement resorption (ankylosis), slight

inflammatory resorption, and severe inflammatory resorp­

tion. Each of the 30 sections from each tooth segment

was given a numerical sco~e from zero to four in each of

the five previously described categories. This score was

determined by mentally dividing each section into four quad­

rants, then noting how many quadrants in which the process

56

described in each category was seen. Thus for a given

segment of a tooth a score of between zero and 120 was

given in each histologic category. Twenty teeth studied,

divided into three segments each, with five histologic

categories, resulted in 300 histologic scores. The

results of this examination were charted for each dog

in tables one through six. The radiographs were examined

without knowledge of the corresponding histologic results,

and were also included in these tables, along with the

clinical periodontal observations.

The histologic categories were based on Andreasen's

(43) three types of external root resorption, with the

added classifications of normal (unresorbed) cementum. It

was found during examination of the sections that inflamma­

tory resorption was seen in two extremes. One was called

slight inflammatory resorption, and showed shallow punched

out areas through the cementum, extending into the dentin

not more than one quarter of its thickness. The periodontal

ligament in these areas showed mild inflammatory cell in­

filtration, with occasional osteoclasts present along the

dentinal walls of the resorbed defects. Repair of resorp­

tion by cementum was sometimes seen adjacent to th~se areas.

The second type was called severe inflammatory resorption,

and was seen as large areas of granulomatous tissue extend­

ing from the periodontal ligament deep into the dentin,

57

often encompassing one-quarter to one-half of the tooth in

cross section, and extending into the root canal space. At

the interface with the dentin, under high-power examina­

tion, was seen scooped-out areas of resorption, most

filled with a multinucleated osteoclastic cell (figure 12, 13.)

The granulomatous tissue was composed of a loose connective

tissue framework with many capillaries, densely infiltrated

with many polymorphonuclear leukocytes and lymphocytes,

with occasional plasma cells, macrophages, and giant cells.

These two types of inflammatory resorption were probably

differing degrees of the same pathologic process, or ar­

rested and active forms. Nevertheless, they appeared in

separate and distinct areas, with little gradation in

between. For the purposes of comparing the two filling

materials, the presence of each type of inflammatory res­

orption was computed separately. Inflammatory resorption

was seen radiographically as radiolucent areas within the

tooth or bone (figure 14, 17.)

The maxillary left incisor of dog number two, filled

with calcium hydroxide, was cut in two by severe inflammatory

resorption, with loss of the cervical two thirds of the

tooth. Histologic sections through the cervical area showed

a massive infiltration of plasma cells, indicating a severe

inflammatory response (figure 18,19.) It is possible that this

might suggest the presence of an autoimmune response.

58

The third histologic category was replacement resorp­

tion, or ankylosis. Histologically, this was seen as areas

of resorbed dentin fused intimately with alveolar bone

(figure 3, 8.) This was seen sometimes as isolated tra­

beculae of bone occasionally in contact with dentin, or

as large areas of contact, sometimes involving almost the

entire periphery of the root. Osteoblasts were often seen

lined up along the periphery of the dentin and bone, in­

dicating active bone formation, even at the 90 day sacri­

fice time. Radiographic findings in ankylosis included

disappearance of the normal periodontal ligament space,

and continuous replacement of resorbed root surface with

bone (figure 9. )

The most prevalent histologic category seen in this

study was surface resorption repaired by cementum. Small

resorptive lacunae were seen along the dentin and cementum

surface, repaired by cellular secondary cementum (figure 5.)

A normal periodontal ligament was present. This type of

resorption was also seen in areas of the roots of unoper­

ated control teeth, and is evidently an area of spontaneous

repair of small areas of damaged cementum.

The fifth histologic category was the presence of

normal periodontal ligament and unresorbed cementum (figure

3.) There were relatively few areas showing this lack of

root resorption, although it was more prevalent in cervical

areas than in apical or middle. Both repaired surface

resorption and normal ligament and cementum were seen

radiographically as having a normal periodontal space

around the replanted tooth.

It must be stressed that never was an entire root

59

or root-third seen histologically as fitting into one

category of healing or resorption. Usually even one his­

tologic cross-section showed two or three categories (figure

3.) For example, repaired surface resorption was often

interspersed with areas of ankylosis, and even severe

inflammatory resorption was seen in the same cross-section

with normal cementum and periodontal ligament. From this

it is obvious that accurate radiographic interpretation of

the root resorptive processes is impossible, unless a large

area is grossly affected.

The three teeth in dog number four, which were exfol­

iated because of extensive inflammatory root resorption,

were histologically scored as showing total inflammatory

root resorption, given 120 points at each level, even

through by the 90 day sacrifice time the sockets were in an

advanced state of healing. The inflammatory resorption was

clearly evident in the 30 day radiographs, with large radio­

lucent areas surrounding the roots, leading to exfoliation.

By 90 days radiographic evidence of bony healing of the

sockets could be seen.

60

The Procion vital dye was not seen to fluoresce as

was expected when unstained sections, or th~estained with

hematoxylin and eosin, were examined with the fluore­

scent microscope. Unresorbed cementum on unreplanted

control teeth and on a very few sections of replanted

teeth demonstrated a darker-staining red band in the

hematoxylin and eosin stained sections. Without the con­

firmation of the fluorecence, it was not determined

whether this was a layer of secondary cementum laid down

and stained by the vital dye, or merely a zone of darker

staining by the hematoxylin and eosin.

Table 7 shows a summary of the histologic scores for

all twenty teeth, grouped according to the five histologic

criteria studied, the three segrrents of the teeth studied,

and the two different canal filling materials used. Since

the purpose of this study was to determine whether a dif­

ference in root resorption would be seen between teeth

filled with gutta-percha and sealer or calcium hydroxide,

the histologic results were subjected to statistical ana­

lysis. Within each of the five resorption catagories

studied, and for each third of the root surface studied, a

two-sample t-test was applied, comparing the scores of

the ten teeth filled with each material. The formulas used,

the limits at 5% and 1% probability, and the t-test results

61

can be seen in Table 8. The results showed no statistically

significant difference in histologic scores between the two

filling materials, at either the 5% or 1% level of proba­

bility, at any level of the root examined. Since no

differences were seen within any of the groups as divided

according to root third, statistical analysis of the total­

tooth scores was thought to be unnecessary and was not done.

In Table 9, the teeth were grouped in the same cate­

gories, but the histologic results were evaluated to spe­

cifically comparethe paired contralateral teeth, one

filled with each material. This may also be a valid

analysis, because variations in healing and tissue response

between animals are eliminated. For each category including

ten pairs of teeth, the number of teeth filled with each

filling material showing the higher score of the pair in

each category of evaluation is listed. The number of

times the two teeth showed equal scores in a given cate­

gory is also shown. Careful examination of this table

may give additional information beyond the point totals and

statistical analysis in tables seven and eight.

TABLE 1 Normal Surface ~eplacement Slight Severe

Dog Ill Periodonta Resorption, Resorption Inflammat. Inflammat. Ligament & Regenerate( (Ankylosis) Resorption Resorption Cementum P. D. L.

Histologic Scores, 30 sections each 1/3, scored 0-120 Maxillary Apical 8 84 82 5 0 Incisor Gutta- Middle 4 56 117 7 0 Percha

Cervical43 49 55 34 0

Maxillary Ap. 0 53 76 17 11 Incisor Ca(OH) 2 Mid. 12 106 81 20 0

Cerv. 34 63 14 38 30

Mandibular Incisor Gutta- Tooth fractured during extraction Percha

Mandibular Incisor Ca(OH) 2 Tooth not extracted

Radiograph. Appearance

-

Good, mild Ankylosis

II

II

Good, mild Ankylosis

II

II

~linical Periodonta !Appearance

Tooth firm, gingiva

uninflamed

Tooth firm, gingiva

uninflamed

0'1 N

TABLE 2 Normal Surface ~eplacement Slight Severe Radiograph. Clinical

Dog 112 Periodontal Resorption, Resorption Inflammat. Inflammat. Appearance ,Periodonta Ligament & Regenerated (Ankylosis) Resorption Resorption Appearance Cementum P, D. L,

Histologic Scores, 30 sections each 1/3, scored 0-120 IMild Tooth Maxillary Apical 0 68 75 55 0 ~nkylosis slightly Incisor mobile, Gutta- Middle 6 49 113 58 0 II gingiva Percha slightly

Cervical 2 44 29 47 10 Inflammat. inflammed resorption

Maxillary Ap. 0 49 68 32 59 Inflammat. Crown lost, Incisor resorption periodonta, Ca(OH) 2

tissues Mid. 0 0 0 0 120 II inflammed

Severe inf. resorption,

Cerv. 0 0 0 0 120 crown lost

Ap. 0 96 0 30 0 Good Tooth Mandibular firm, Incisor Mild gingiva Gutta- Mid, 15 105 0 21 0 ankylosis uninflamed Percha

Cerv. 0 66 0 37 86 Inflammat. resoq~_tion

Mandibular Ap. 0 65 10 25 30 Very good Tooth 'Incisor firm, Ca(OH) 2 Mid. 27 82 30 33 0 Very good gingiva

uninflamed

Cerv. 0 120 0 20 0 Very good

TABLE 3 Normal Surface ~eplacement Slight Severe Radiograph. Clinical Periodontal Re~orption, ~esorption Inflammat. Inflammat. lA ppearance Periodmtal

Dog lf3 Ligament & Regenerated (Ankylosis) Resorption Resorption Appearance Cementum P. D. L.

Histologic Scores, 30 sections each 1/3, scored 0-120 !Fairly Maxillary ~pical 0 0 0 0 120 severe Tooth Incisor !ankylosis firm, Gutta- Middle 0 0 120 0 0 ~evere gingiva Percha

ankylosis uninflamec

~ervical 38 31 45 25 0 Good

~p. 0 26 99 40 0 Fairly Tooth ~evere Maxillary ~nkylosis

firm, Incisor gingiva Ca(OH) 2 Mid. 24 35 57 52 0 Mild uninflamed

~nkylosis

~erv. 30 20 38 21 9 ~ood

~p. 0 57 0 45 17 Severe Tooth linflammat. Mandibular Ire sorption slightly

Incisor mobile, Gutta- Mid. 23 53 49 38 0 ~ood gingiva Percha inflamed

Cerv. 45 90 0 63 0 ~ood

~p. 0 42 58 44 0 ~~ld Tooth Mandibular linflammat. firm, Incisor Ice sorption gingiva Ca(OH) 2 Mid. 30 49 88 37 0 Good uninflamed

~erv. 64 52 10 50 0 Good

Dog /}4

Maxillary Incisor Gutta-Percha

Maxillary Incisor Ca(OH) 2

Mandibular Incisor Gutta-Percha

Mandibular Incisor Ca(OH) 2

TABLE 4 Normal :>urface IKeplacenent !~light !Severe PeriodontalResorption, Resorption Inflammat. Inflammat. ~igament & Regenerated (Ankylosis Resorption Resorption Cementum P. D. L.

Histolo~ic Scores 30 SP('f"i(ms Ml('h 1/3 scoren 0-120 Apical I I I I 120

Severe inflammatory resorption, Middle tooth exfoliated by 30 days. 120

Cervical 120 Ap.

I 120

Severe inflammatory resorption, Mid. tooth exfoliated between.30 and 120 60 days.

Cerv. 120

Ap. 120 Severe inflammatory resorption, tooth exfoliated before 30 days.

Mid. 120

Cerv. 120 Ap. 0 55 70 26 0

Mid. 10 63 73 21 0

Cerv. 38 71 33 30 0

Rad~ograph. Clin~cal Appearance Periodamal

Appearance

Healing Gingiva socket healed by 90 days by 90 day~

Healing Gingiva socket healed by 90 days by 90 dayE

Healing Gingiva socket healed by 90 days by 90 dayE

Good Tooth firm, gingiva

Good uninflamed

Good 0\ VI

TABLE 5 ~ormal Surface ~eplacement Slight Severe ~adiograph. Clinical

Dog :f}5 Periodontal Resorption, ~esorption Inflammat. Inflammat. ~ppearance Periodonta !Ligament & Regenerated Ankylosis) Resorption Resorption 1\ppearance Cementum P, D, L,

Histologic Scores, 30 sections each 1/3, scored 0-120 Mild Maxillary A. pi cal 21 48 53 19 0 ankylosis Tooth Incisor Mild firm, Gutta- !Middle 25 83 88 20 0 ankylosis gingiva Percha uninflamec

Cervical 0 15 61 33 85 Seybre tgs i!i'J~!Sfl lAp. 1 45 80 40 0 ~oderate Tooth

Maxillary infl. or firm, replac, res. Incisor Severe

gingiva Ca(OH) 2 ~id. 1 71 84 41 0 inflammat. uninflamec

resorption

Cerv. 29 50 46 33 27 Good

Mandibular Incisor Tooth fractured during extraction Gutta-Percha

Mandibular Incisor Tooth not extracted Ca(OH) 2

TABLE 6 Normal Surface l<.eplacement Sl~ght Severe Radiograph. f.-linical

Dog i!6 Periodontal Resorption, Resorption Inflarnrnat. Inflammat. Appearance Periodonta Ligament & Regenerated {Ankylosis) Resorption Resorption ~ppearance Cementum P. D. L.

Histologic Scores, 30 sections each l/3, scored 0-120 Mild Maxillary Apical 2 57 120 0 0 ankylosis Tooth Incisor firm, Gutta- Middle 0 45 120 10 0 Severe gingiva Percha ankylosis uninflamec

Severe Cervical 7 33 66 35 0 ankylosis

Ap. 0 43 120 58 0 Severe Tooth Maxillary ankylosis mobile, Incisor Very sae:re gingiva Ca(OH) 2 Mid. 12 70 120 63 0 inflammat. uninflamec

resorption

Cerv. 24 32 0 34 45 " Ap. 0 68 120 73 0 Mild infl. Crown

Mandibular resorption lost, Incisor gingiva Gutta- Mid. 0 65 101 80 16 Severe infl inflamed Percha resorption

Cerv. 0 0 0 0 120 Crown lost

Ap. 0 82 88 42 0 Good Tooth

Mandibular ! firm,

Incisor gingiva Ca(OH) 2

Mid. 37 81 88 38 0 Good uninflamec

Cerv. 33 91 0 68 0 Good

TABLE 7 Summarized Histologic Scores

Normal Surface Replacement Periodontal Resorption, Resorption Ligament & Regenerated (Ankylosis) Cementum P. D. L.

Gutta-percha

Apical 1/3 25 478 450

Ca(OH) 2 1 460 669

Gutta-percha

Middle 1/3 73 456 708

Ca(OH) 2 153 557 621

Gutta-percha 135 328 256

Cervical 1/3

Ca(OH) 2 252 499 141

Gutta-percha 233 1262 1414

Totals

Ca(OH) 2 406 1516 1431

Slight Inflammatory Resorption

227

324

234

305

274

294

735

923

Severe Inflammatory Resorption

377

220

356

240

541

351

1274

811 "' 00

TABLE 8 Statistical Analysis

Two-sample t-test applied to histologic results of Table 7, comparing the two filling materials tested.

where s ~ = ___ < x ..... 1:;........-_. _x..;:;.1_)_2

_+ __ <_x..:2.__-_-_x:::.2 _) 2_

(N1 - 1) + (N2 - 1)

Both N1 and N2 are constant at 10, therefore degrees of freedom is 18.

Apical

Middle

Cervical

At~= .05, limits are +2.10

At«= .01, limits are +2.88

Normal Surface Replacement Periodontal Resorption, Resorption Ligament & Regenerated (Ankylosis) Cementum P. D. L. II t II value comp ~ring gutta-per pha vs. Ca(OH) 2

1.16 0.135 -1.09

0.151 -0.634 0.413

-1.30 -1.10 1.07

Slight Severe Inflammatory Inflammatory Resorption Resorption

-0. 97 6 0.715

-0.657 0.480

-0.212 0.815 0\ \o

APICAL 1/3

MIDDLE 1/3

CERVICAL 1/3

TOTAL

TABLE 9

Comparison of Contralateral Gutta-Percha and Ca(OH) 2 filled Teeth

Normal .surface Replacement Periodontal Resorption & Resorption Ligament & Regenerated (Ankylosis) Cementum P. D. L. NUMBER OF TEETH SHOWING THE HIGHER HISTOLOGIC

G-P Higher 3 6 3

CH Higher 0 3 5

Equal 7 1 2

G-P Higher 2 4 5

CH Higher 7 5 3

Equal 1 1 2

G-P Higher 3 4 5

CH Higher 5 5 2

Equal 2 1 3

G-P Higher 8 G-P 14 G-P 13

CH Higher 12 CH 13 CH 10

Equal 10 Equal 3 Equal 7

Slight Severe Inflammatory Inflammatory Resorption Resorption

SCORE IN EACH CATAGORY

4 3

6 3

1 4

3 2

6 2

1 6

5 4

3 4

2 2

G-P 12 G-P 9

CH 14 CH 9

Equal 4 Equal 12

CHAPTER V

DISCUSSION

The results of this study indicate that it was im­

possible to demonstrate a difference in any type of root

resorption at any level of the root when calcium hydroxide

was used as an immediate root canal filling material, when

compared with gutta-percha and sealer. No extensive con­

clusions, however, should be made from the data presented

here. Due to the low sample size (twenty teeth) and be­

cause only one set of experimental replantation conditions

were used, further work in this area would seem to be war­

ranted. The effects of a different extraoral time and

environment are unknown as to their interaction with the

role of the canal filling material. The time of placement

of the calcium hydroxide canal dressing also may be very

important. The studies that showed promising results with

calcium hydroxide in the.arrest of root resorption all had

the paste being placed into the canals at sometime after

replantation, after resorption had begun, and after some

periodontal ligament heal~ng had taken place. Andreasen

(81) has suggested that calcium hydroxide placed into the

root canal at the time of replantation may act as a. necro­

tizing agent to an unregenerated periodontal ligament,

preventing initial healing. Therfore, he suggested canal

debridment one week after replantation, with delay of calcium

71

72

hydroxide placement for two more weeks after that, to

allow for primary healing of the periodontal ligament.

This may act as a natural barrier to prevent a gross

flooding of the socket with the caustic, highly alkaline

calcium hydroxide. Nevertheless, in this study the calcium

hydroxide treated teeth showed no worse resorption than

the gutta-percha and sealer treated teeth. Gutta-percha

has been shown by many studies, including Feldman and

Nyberg (155) 1 to be very well tolerated by the tissues,

while Procosol sealer has been shown by Kapsimalis and

Evans (156) to have excellent sealing ability, and by

Rappaport (157) to evoke a very mild inflammatory response

in rat connective tissue. Therefore, this combination

should serve as a good control with which to compare the

effects of the calcium hydroxide. Further study into the

precise effect of calcium hydroxide, in the root canal,

on the periodontal tissues after replantation G warranted.

The material has such proven effects on pulpal and periapical

tissues when used as a capping or apexification agent that

it would be surprising if it had no effect when used in

replanted teeth. Other experiment conditions other than

those in the present study should be evaluated.

Calcium hydroxide has been shown to definitely alter

dentin, which may transmit changes through the tubules to

the cementum surface and periodontal ligament. Linden (158)

73

demonstrated, with an in vitro study, the presence of

molecular level pathways of communication between the pulp

chamber and the root surface. Calcium hydroxide is a small

molecule, so it may be able to penetrate these tubules.

It is not clear which part of the calcium hydroxide

molecule exerts the active effect on pulp, dentin, and

periapical tissues. Sciaki and Pisanti (159) and Pisanti

and Siaki (160) demonstrated, by the use of labeled calcium

ions, that the calcium used in the formation of the dentin

bridge over a healing pulp cap is not contributed by the

calcium hydroxide, but comes from the circulating serum

calcium. Raisz (161), studying the osteoclastic resorption

of fetal rat bone in tissue culture, stimulated by parathor­

mone, found that raising the calcium ion concentration

from five to'twelve mg./100ml. had no effect on the rate

of active bone resorption. An increased calcium ion

content, however, did cause a decrease in mineral loss,

through a decrease in dissolution of bone mineral. In a

similar study, Raisz and Niemann (162) found that while a

calcium ion increase did not affect active bone resorption,

an increased phosphate concentration significantly decreased

parathormone-induced osteoclastic resorption of bone in

tissue culture. Possibly a high-phosphate root canal filling

should be studied as a root canal filling material for

treatment of root resorption after replantation. Whether

74

the fact that changes in ion concentration have been found

to alter bone resorption, may be extended to include ex­

ternal root resorption is unknown. Orban (163) stated,

however, that osteoclasts are the active cells in both

bone resorption and resorption of the roots of teeth, so

research findings on bone resorption, although a separate

process, may be at least partially applicable to root

resorption.

The extreme alkalinity of calcium hydroxide, usually

reported to be around pH 12, has been suggested as being

responsible for its actions on tissue. Laws (164) found

that the pH of calcium hydroxide from a treated pulpotomy

was 7.4, the decrease attributed to dilution by the sur­

rounding tissue fluids, whose pH may have been at the same

time raised somewhat. This pH effect has been suggested

by SchrBder and Granath (120) as being the cause of the

dentin bridging under a pulp cap by irritation of remaining

pulp tissue. Raisz (161) found in his tissue culture study

that parathormone could stimulate osteoclastic bone resorp­

tion from pH 6·.78 to 7.45. Raising the pH to 7.6 with

bicarbonate inhibited the bone resorption significantly.

This is near the pH of the spent calcium hydroxide after

equilibration with tissue fluid reported by Laws. Although

it has not been proven directly, it would seem to follow

that perhaps calcium hydroxide, when placed in the root

75

canal, may, by penetration through the dentinal tubules or

apical foramena, have a direct effect on osteoclastic

resorption after replantation.

Menkin (165) created a severe inflammatory response

in the pleural cavity of dogs by injecting irritants. He

discovered that as the inflammation progressed, the exudate

became more acidic. When the pH increased, however, the

outlook was more favorable and the animal tended to improve.

It is possible that calcium hydroxide may change the en­

vironment of the periodontal ligament from one of inflam­

mation and resorption to a more alkaline pH which is more

conducive to healing and calcification of resorbed areas.

Even though calcium hydroxide has been shown by Spangberg

(166, 167) to be highly toxic to HeLa cells and human skin

fibroblasts in tissue culture, it has also been demonstrated

that it can induce calcification in connective tissue of

rats by both Mitchell and Shankwalker (168) and Binnie and

Mitchell (153). This calcification was described as being

an "osteoid" material, which is morphologically very similar

to secondary cementum, the method by which root resorption

is healed.

Binnie and Rowe (169) found that calcium hydroxide

materials seemed to be particularly useful in an infected

environment, when used as a root canal filling material.

Cvek (170), in studying apexification of teeth with

76

pulp necrosis and periapical pathosis, " assumed that

calcium hydroxide per §Q may act as a long-acting anti­

bacterial agent." Fisher (171) found that viable micro­

organisms were not recoverable from previously infected

carious dentine in vital permanent teeth exposed to a

lining paste of pure calcium hydroxide and water, while

simple isolation did not kill the organisms. Matsumiya

and Kitamura (137) filled experimentally infected root

canals in dogs with a calcium hydroxide paste. They found

that bacteria living in the periapical tissues were clearly

observed to diminish and disappear as healing progressed.

They concluded that "calcium hydroxide has an antibacterial

effect in the dental tissue." Since Andreasen (46) attri­

butes inflammatory root resorption after replantation

largely to infected necrotic tissue within the root canal

escaping through dentinal tubules, especially in young

teeth, perhaps the antibacterial effects of calcium hydroxide

would be beneficial to the periodontal healing of this type

of resorption. To what extent this is true has not yet

been proven.

All of these theories on the possible modes of action

of calcium hydroxide on replanted teeth·must remain theories

until proven. They are not consistent with the findings

of the present study. Within its very limited confines,

therrresults showed no discernable differences in several

types of root resorption between calcium hydroxide-filled

teeth, and teeth filled with gutta-percha and sealer,

which are control materials well accepted as being

relatively innocuous in their effect on tissue.

Splinting for 30 days may have had an effect on

the results of this study, possibly causing higher inci­

dence of ankylosis than if they had been removed at

77

one week as recommended by Andreasen (44). Whatever

effect that this had, however, would have been shared

equally by teeth filled by both methods. It was effective

in preventing exfoliation of teeth through eating and

chewing, before the regenerating periodontal ligament

had enough strength of its own.

As in any animal study, great care must be taken

when extrapolating results to humans. Although Nygaard­

Ostby (121) and Matsumiya and Kitamura (137) found similar

healing in humans and dogs, Gad (172) found that periodontal

disease progressed five times as fast in dogs than in

humans. Whether or not there is a similar difference in

healing after replantation is unknown, as no controlled

studies have been done in this area.

Systemic .conditions and individual healing variations

may have great effect on the healing and subsequent re­

sorption of replanted teeth. All replanted teeth in five

dogs in this study remained in the socket, with varying

degrees of resorption, by the termination of the study.

Dog number four, however, had three teeth exfoliate

_78

because of gross inflammatory resorption, even though all

six animals were treated identically throughout the study.

Why this dog reacted so differently to the treatment is

unknown, but the fact that there was such a variation

between animals leads to the conclusion that systemic

healing differences may account for some of the clinical

unpredictability of replantation.

Most clinical replantation studies are largely

evaluated radiographically, unless the teeth are extracted

because of failure of treatment. In general, in this study,

the correlation between radiographic and histologic results

was good only when an advanced state of pathosis was

present, such as severe inflammatory root resorption. More

moderate resorption was often difficult to diagnose properly

by the use of the radiograph. Often the loss of the

integrity of the lamina dura and lack of sharpness of

detail of the root surface was evident radiographically.

Microscopic examination, however, revealed anything from

repaired surface resorption to moderate ankyosis or mild

inflammatory r~sorption, or a combination of histologic

entities. Care should be taken in evaluating replanted

teeth radiographically, especially when testing various

methods of treatment.

It is not known why the Procion vital dye was not

seen in the histologic sections. Procion red H-8BS has

79

been reported in the literature to stain bone and cemen­

tum that was being laid down while the dye was present in

the circulation. When an attempt was made to purchase

this dye from the manufacturer, their representative stated

that Procion H-8B reactive red 31 had replaced, and was

identical to1 Procion red H-8BS, so the former is what

was used in this study. They may have been in error,

however, because the dye was not seen in unstained sections,

and no fluorescence was seen. The dye may have stained

collagen but not calcified tissues, it may have been

removed from bone and cementum during fixation and de­

calcification, or it may show no fluorescence even if

present. Its importance to the study was not critical,

however, and its use was intended merely as a tool to see

whether resorption occurred before or after the 30 day

time that it was injected, by the presence or absence of

a fluorescent ring of cementumo

SUMMARY AND CONCLUSIONS

Twenty maxillary and mandibular incisors in six

beagle dogs were extracted and replanted after drying

in sterile gauze for one hour. During that hour, the

root canals were debrided, prepared, and filled, half

with gutta-percha and sealer, and half with a pa~te ·made

of calcium hydroxide and camphorated parachlorophenol.

The animals were radiographed and observed for ninety

days, at which time they were sacrificed. Histologic

sections were examined and graded in five categories

ranging from normal cementum to severe inflammatory re­

sorption. The histologic results were statistically

evaluated to determine whether or not there was a difference

in root resorption when the teeth were filled with calcium

hydroxide paste or gutta-percha and sealer. The experi­

ment showed the following:

a) All the replanted teeth showed extensive resorp­

tion when examined histologically, ranging from

surface resorption repaired by cementum depo­

sition to severe anklosis or inflammatory

resorption.

b) The reaction at the surface of an individual

tooth was not uniform. Usually one type of

resorption was seen in close relationship to

another, in almost any combination. This was

80

81

true within the same histologic cross-section,

and also between different levels of the root

from apex to cervix.

c) This study was unable to demonstrate, at any

level of the root, any statistically significant

differences in any type of resorption between

teeth filled with calcium hydroxide or gutta-

percha and sealer.

d) Radiographic examination proved inadequate in ,

critically evaluating the results of replantation.

Only large areas of resorption were correctly

interpreted radiographically, when compared

with histologic sections.

e) No broad conclusions as to the value of calcium

hydroxide in treating or preventing root resorp-

tion in replanted teeth should be made from these

results alone. Due to the limited number of

teeth and the single set of replantation condi-

tions, thisstudy should be regarded as a pilot

study. Further work is necessary using varied

extraoral times and environments, as well as

with delayed placement of the calcium hydroxide

paste for several weeks after replantation.

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96, Monsour, F.N,: Pulpal changes following the reim­plantation of teeth in dogs: a histologic study, Aust. Dent. J, 16 (4): 227, 1971,

" 97, Ohman, A.: Healing and sensitivity to pain in young replanted human teeth. An experimental, clinical, and histologic study, Odont. T, 73: 165, 1965,

" 98. Ohman, A.: Healing and sensitivity to pain in young teeth, Odont. T, 73: 211, 1965.

99. Smith, H,J.: Successful replantation. A case report, Br. Dent. J, 139 (3): 105, 1975.

100. Whiteacre, G,W,, and Edwards, J,L,: Re-implantation of avulsed teeth, NZ Dent. J, 72: 96 1976.

101. Heithersay, G.S.r Replantation of avulsed teeth. A review, Aust. Dent, J, 20 (2): 63, 1975.

102. Barndt, R,, and Hoefig, W.: Replantation of trau­matically avulsed teeth, Quintessence Int. 3 (5): 19, 1972.

90

103. Marosky, J.E.: Treating the avulsed tooth, J. Mass. Dent. Soc. 26 (3): 235, 1977.

104. McKinley, B.: Treatment of external root resorption following avulsion and reimplantation of a maxillary central incisor, Alaska Med. J, 15 (3): 73, May, 1973.

105. Hermann, B.W.: Dentinobliteration der Wurzelkanaele nach der Behandlling mit Kalzium, Zahnarzt Rundsch 39: 888, 1930.

106. Zander, H.A.: Reaction of the pulp to calcium hydrox­ide, J. Dent, Res. 18: 373, Aug. 1939.

107. Glass, R.L., and Zander, H.A.: Pulp healing, J. Dent. Res. 28: 97 , 1 94 9.

108. Mjor, I.A.: Histologic studies of human coronol den­tin following the insertion of various materials in experimentally prepared cavities, Arch. Oral Biol. 12 (4): 441, 1967.

109. Avery, J.K.: Response of the pulp and dentin to con­tactly filling materials, J. Dent. Res. 54, spec. no. 8, PB 188, June 1975.

110. Heys, D.R., Heys, R.J., Cox C.F., and Avery J .K.: Histopathologic evaluation of the effects of 4 calcium hydroxide liners on monkey pulps, J. Oral Pathol. 5 (3): 129, 1976.

111. Macchetti, D.O., Toledo, O.A.: Secondary mineraliza­tion of rat molar healthy dentin by means of calcium hydroxide: A fluorescence study, J. Dent. Child. 38 (4): 247, 1971.

112. Eidelman, E., Finn, S.B., Koulourides, T.: Reminer­alization of carious dentin treated calcium hydroxide, J. Dent. Child. 32 (4): 218, 1965.

113. Spedding, R.H., Mitchell, D.F., and McDonald R.E.: Formocresol and calcium hydroxide therapy, J. Dent. Res. 44 (5): 1023, 1965.

114. Kozlov, M., and Massler, M,: Histologic effects of various drugs on amputated pulps of rat molars, Oral Surg. 13 (4): 455, 1960.

91

115. Krakow, A.A., Berk, H., and Gron, P.: Therapeutic induction of root formation in the exposed incom­pletely formed tooth with vital pulp, Oral Surg, 43 (5): 755, 1977.

116. Moodnik, R.: Clinical correlations of the devel­opment of the root apex and surrounding structures, Oral Surg. 16 (5): 600, 1963.

117. Via, W.: Evaluation of deciduous molars treated by pulpotomy and Ca(OH) 2 JADA 50 (1): 34, 1955.

118. Schr8der, u., and Granath, L.G.: On internal dentin resorption in deciduous molars treated by pulpotomy and capped with calcium hydroxide, Odontol. Revy. 22 ( 2) : 1 7 9 ' 1 971 •

119. Schr8der, U.: Evaluation of healing following ex­perimental pulpotomy of intact human teeth and cap­ping with calcium hydroxide, Odontol. Revy. 23 (3): 329, 1972.

120. Schr8der, U., and Granath, L.: Early rxn of intact human teeth to Ca(00)2 follaving experimental pulpotomy and its significance to the development of hard tissue barrier, Odontol. Revy, 22 (2): 379, 1971.

121. Nygaard-Ostby, B.: The role of the blood clot in endodontic therapy, Act. Odontol. Scand. 19: 323-353, 1961.

122. Kaiser, H.J.: Management of wide open canals with calcium hydroxide, Read before the American Assoc. of Endodontists,Washington, DC, April 17, 1964.

123. Frank, A.L.: Therapy for the divergent pulpless tooth by continued apical formation, JADA 72:87, Jan. 1966.

124. Michanowicz, J.P., and Michanowicz, A.E: A conserva­tive approach and procedure to fill an incompletely formed root using calcium hydroxide as an adjunct, J. Dent. Child. 32: 42, 1967.

125. Frank, A.L.: Treatment of the wide open apex, Dent. Clin. N. Am, p. 688, No~, 1967.

92

126. Steiner, J.C., Dow, P.R., and Cathey, G.M.: In­ducing root end closure of non-vital permanent teeth, J. Dent. Child 35: 47, 1968.

127. Van Hassel, H.J., and Natkin,E.: Induction of root end closure, J. Dent. Child. 37: 57, 1970.

128. Dylewski, T.: Apical closure of non-vital teeth, Oral Surg, 32: 82, 1971.

129. Steiner, J.C., and Van Hassel, H.J.: Experimental root apexification in primates, Oral Surg. 31: 409, 1971.

130. Torneck, C.D., and Smith, J.: Biological effects of endodontic procedure on developing incisor teeth, Oral Surg. 30: 258-266, 1970.

131. Torneck, C.D., Smith, J., and Grindall: Biological effect of endodontic procedures m developing incisor teeth, part II. Effect of pulp injury and contamination Oral Surg, 35: 378, 1973.

132. Torneck, C.D., Smith, J., and Grindall, P.: Biologi­cal effects of endodontic procedures on developing incisor teeth, part III, effect of debridment and disinfection procedures in the treatment of experi­mentally induced pulp and periapical desease, Oral Surg. 35: 532, 1973.

133. Torneck, C.D., Smith,~' and Grindall, P.: Biologic effects of endodontic procedures on developing incisor teeth, part IV, effect of debridment procedures and Ca(OH)2 - CMCP paste in the treatment of experimentally induced pulp and perapical desease, Oral Surg. 35: 541, 1973 0

134. Ham, J., Patterson, S., and Mitchell, D.: Induced apical closure of immature pulpless teeth in monkeys, Oral Surg. 33: 438, 1972.

135. Roberts, S.C., and Brilliant, J.D.: Tricalcium phos­phate as an adjunct to apical closure in pulpless permanent teeth, compared to Ca(OH)2, J. Endod. 1 (8): 263' 197 50

93

136. England, M.C., and Best, E.: Noninduced apical closure in immature roots of dog's teeth, J, Endod. 3 (11): 411, 1977.

137, Matsumiya, S,, and Kitamura, M,: Histo-pathological and histo-bacteriological studies of the relation between the condition of sterilization of the in­terior of the root canal and the healing process of periapical tissues in experimentally infected root canal treatment, Bull. Tokyo Dent, Coll. 1: 1 p.l, 1960.

138, Holland, R., DeMello, W., Nery, M,J., Bernabe, F.E., and DeSouza, V.: Reaction of human periapical tissue to pulp extirpation and immediate root canal fillingwithcalciumhydroxide, J, Endod, 3 (2): 63, 1977'

139. Martin, D.M., and Crabb, B.S.: Calcium hydroxide in root canal therapy. A review, Br. Dent, J, 142 (9): 277, 1977 0

140. Stromberg, T.: Wound healing after total pulpectomy in dogs. A comparative study between root fillings with calcium hydroxide, dibasic calcium phosphate, and gutta-percha, Odontol. Revy. 20 (2): 147, 1969.

141. Weinstein, T., and Goldman, M.: Apical hard-tissue deposition in adult teeth of monkeys with use of calcium hydroxide, Oral Surg. 43 (4): 627, 1977.

142. Frank, A.L., and Weine, F.S.: Non-surgical therapy for the perforative defect of internal resorption, J, Am. Dent. Assoc. 87: 863, 1973.

143. Frank, A.L,: Resorption, perforations, and fractures, Dent. Clin. North Am. 18 (2): 465, 1974.

144. Stewart, G,G,: Ca (OH)2 induced root healing, J. Am, Dent. Assoc. 90: 793, 1975,

145. Sinai, I.H.: Endodontic perforations: their prognosis and treatment, J. Am. Dent. Assoc. 95 (1): 90, 1977.

146. Cvek, M.: Clinical procedures promoting apical clo­sure and arrest of external root resorption in non­vital p~rmanent incisors, Trans. Int. Conf. Ended. 5: 30, 1973.

94

147, Cvek, M.: Treatment of non-vital permanent incisors with Ca(OH)2, II, effect on external root resorption in luxated teeth compared with effect of root filling with gutta-percha - a follow up, Odontol. Revy. 24: 343 1 1973 o

148. Burke, J,H.: Reversal of external root resorption, J. Endod. 2 (3): 87, 1976.

149. Hoyte, D.: Alizarin red in the study of the appo­sition and resorption of bone, Am. J. Phys. Anthrop. 2 9 I 15 7 1 1 968 o

150. Frost, H.: Tetracycline bone labeling in anatomy, Am. J. Phys. Anthrop. 29: 183, 1968.

151. Goland, P., and Grand N.: Chloro-S-Triazines as markers and fixatives for the study of growth in teeth and bones, Am. J. Phys. Anthrop. 29: 201, 1968.

152. Prescott, G., Mitchell, D., and Fahrny, H.: Procion dyes as matrix markers in growing bone and teeth, Am. J. Phys. Anthrop. 29: 219, 1968.

153. Binnie, W.H., and Mitchell, D.F.: Induced calcifi­cation in the subd<:~rmal tissues of the rat, J. Dent. Res. 52: 1087, 1973.

154. Reames, R.L., Nickel, J.S., Patterson, S.S., Boone, M., and El-Kafrawy, A.H.: Clinical, radiographic, and histologic study of endodontically treated retained roots to preserve alveolar bone, J. Endod. 1 (11): 367, 1975.

155. Feldman, G., and Nyborg, H.: Tissue reaction to root filling materials, Odontol. Revy. 13: 1, 1962.

156. Kapsimalis, P., and Evans, R.: Sealing properties of endodontic filling materials using radioactive polar and nonpolar isotopes, Oral Surg. 22: 386, 1966.

157. Rappaport, H.M.: Toxicity of endodontic filling materials, Oral Surg. 18: 785, 1964. ·

158. Linden, L.: Microscopic observation of fluid flow through cementum and dentin. An in vitro study on human teeth, Odontol. Revy. 19: 367, 1968.

159. Sciaky, I., and Pisanti, S,: Localization of calcium placed over amputated pulps in dog's teeth, J. Dent. Res. 39: 1128,1960.

95

160. Pisanti, S. , and Sciaky, I.: Origin of calcium in the repair wall after pulp exposure in the dog, J. Dent, Res, 43: 641, 1964.

161. Raisz, L.: Bone resorption in tissue culture:Fac­tors influencing the response to parathyroid hormone, J, Clin. Invest. 44 (1), 103, 1965.

162. Raisz, L.G., and Niemann, I.: Effect of phosphate, calcium, and magnesium on bone resorption and hor­monal responses in tissue culture, Endocrinology 85: 446 ' 1 96 9.

163. Sicher, H., ed.: Orban's Oral Histology and Embryo­lQgy, c.v. Mosby Co., 1966.

164. Laws, A.J.: Calcium hydroxide as a possible root filling material, N.Z. Dent. J. 58: 274, 1962.

165. Menkin, V.: Biochemical Mechanisms in Inflammation 2nd ed., p. 67 Springfield, IL, Thomas, 1956.

166. Spangberg, L.: Biologic effects of root canal filling materials, II, effect in vitro of water soluble components of root canal filling material on He La cells, Odontol. Revy. 20: 133, 1969.

167. Spangberg, L.: Biological effects of root canal filling materials, ~· Toxic effect in vitro of root filling materials on He La cells and human skin fibroblasts, Odontol. Revy. 29 (4): 427, 1969.

168. Mitchell, D.F., and Shankwalker, G.: Osteogenic potential of calcium hydroxide and other materials in soft tissue and bone wounds, Ja Dent. Res. 37: 1157' 1958.

169. Binnie, W.H., and Rowe, A.H.R.: A histologic study of the periapical tissues of incompletely formed pulpless teeth filled with calcium hydroxide, J. Dent. Res. 52: 1110, 1973.

170. Cvek, M.: Treatment of non-vital permanent incisors with Ca(OH)2, I. Follow-up of periapical repair and apical closure of immature roots, Odont. Revy. 23, 27, 1972.

96

171. Fisher, F.J.: The effect of a calcium hydroxide­water paste on micro-organisms in carious dentine, Br. Dent. J, 133 (1): 19, 1972.

172. Gad, T.J.: Periodontal disease in dogs, J. Periodont. Res. 3: 268-272, 1968.

FIGURES

97

98

Figure 1: Dog #4, maxillary pre-operative radiograph.

Figure 2: Dog 114, maxillary immediate post-operative radiograph. Tooth on left of photograph filled with Ca(OH)?, contralateral tooth filled with gutta-percha and sealer.

99

1

2

Figure 3:

Figure 4:

100

Dog #3, mandibular incisor, Ca(OH) 2 filling. Unreplanted control tooth (CT), replanted tooth showing normal cementum (NC), severe ankylosis at right (A). (Hematoxylin and eosin stain, original magnification X40),

Surface resorption, repaired with cementum. Schematic drawing from Andreasen (49),

101

4

Figure 5:

Figure 6:

102

Dog #2, mandibular incisor, Ca(OH) 2 filling. Normal periodontal ligament and repairing sur­face resorption. (Hematoxylin and eosin stain, original magnification XlOO).

Dog #2, mandibular 90 day radiograph. Tooth at left, filled with Ca(OH) 7 , showing surface resorption, repaired by cementum. Tooth at right, filled with gutta-percha and sealer, showing cervical severe inflammatory resorption.

103

6

Figure 7:

Figure 8:

104

Progressive replacement resorption (ankylosis). Schematic drawing from Andreasen (49).

Dog #3, maxillary incisor, gutta-percha and sealer filling. Ankylosis. Dentin(D), bone (B), osteoblast (OB), osteoclast (OC). (Hemat­oxylin and eosin stain, original magnification XlOO).

105

Figure 9:

Figure 10:

106

Dog #3, maxillary 60 day radiograph. Tooth at left, filled with gutta-percha and sealer, show­ing ankylosis with spotty inflammatory resorption. Tooth at right, filled with Ca(OH) 2 , showing severe ankylosis.

Severe progressive inflammatory resorption. Schematic drawing from Andreasen (49).

107

9

Figure 11:

Figure 12:

108

Dog #4, mandibular incisor, Ca(OH) 2 filling. Slight inflammatory resorption (SIR) next to normal cementum (NC). (Hematoxylin and eosin stain, original magnification X40).

Dog #1, maxillary incisor, Ca(OH) 2 filling. Cervical severe inflammatory resorption. Granulomatous tissue (GT), active osteoclastic resorption of dentin (OR). (Hematoxylin and eosin stain, original magnification X40).

109

11

Figure 13:

Figure 14:

110

Same histologic section as Figure 12. Higher power view of osteoclasts ~C), or dentinoclasts, in resorptive lacunae in dentin. (Hematoxylin and eosin stain, origional magnification X100).

Dog #4, maxillary 30 day radiograph. Tooth at left, filled with Ca(OH) , showing extreme inflammatory root and bo~e resorption. Tooth at right already lost, residual socket showing diffuse radiolucency with loss of lamina dura.

11 1

14

Figure 15:

Figure 16:

112

Dog 114, maxillary incisor, Ca(OH) 2 filling. Tooth exfoliated because of inflammatory res­orption. Osteoblasts forming bone around residual filling material. ~Hematoxylin and eosin stain, original magnification X40).

Same histologic section as Figure 15. Higher n0wer view of osteoblasts (OB) formir~ h0~~ around mass of connective tissue containing islands of calcified tissue (CT) and granular Ca(OH) 2 particles (CH). (Hematoxylin and eosin stain, original magnification X100).

113

Figure 17:

Figure 18:

114

Dog #2, maxillary 60 day radiograph. Tooth at left, filled with Ca(OH) 2 , showing severe cervical inflammatory root resorption. Tooth at right, filled with gutta-percha and sealer, showing mild ankylosis.

Dog #2, maxillary incisor, Ca(OH) 2 filling. Crown lost because of cervical inflammatory resorption. Epithelium (E) with dense infil­tration of inflammatory cells (IC) in connective tissue. (Hematoxvlin and eosin stain, origi~al magnification X40).

115

17

116

Figure 19: Same histologic section as Figure 18. Higher power view of inflammatory cell infiltration, showing predominance of plasma cells (arrows). (Hematoxylin and eosin stain, origional magnif­ication X400).

117

APPROVAL SHEET

The thesis submitted by Dale M, Anderson, B.S., D. D. S,, has been read and approved by the following committee:

Dr. John V, Madonia, Director Associate Dean, Professor of Microbiology, Loyola University School of Dentistry

Dr. Marshall H. Smulson Professor and Chairman, Department of Endodontics, Loyola University School of Dentistry

Dr. Norman K, Wood Professor and Chairman, Department of Oral Diagnosis, Loyola University School of Dentistry

The final copies have been examined by the director of the thesis and the signature which ap:p:p.rs below verifies the fact that any necessary changes have been incorporated and that the thesis is now given final approval by the Commit­tee with reference to content and form.

The thesis is therefore accepted in partial fulfillment of the requirements for the degree of Master of Science in Oral Biology.