cleaning and shaping of the root canal system edit by hou tiezhou 02988088507

Cleaning and Shaping of Cleaning and Shaping of the Root Canal Systemthe Root Canal System

Edit by Hou TiezhouEdit by Hou Tiezhou

0298808850702988088507

Objectives of Canal PreparationObjectives of Canal Preparation

Start with the end in mindStart with the end in mind

Objectives of root canal preparationObjectives of root canal preparation

The root canal system must be:The root canal system must be: CleanedCleaned of its organic remnants of its organic remnants ShapedShaped to receive a three to receive a three

dimensional filling of the entire dimensional filling of the entire root canal spaceroot canal space

Objectives of root canal preparationObjectives of root canal preparation

The canal isThe canal is Cleansed primarily by irrigationCleansed primarily by irrigation Shaped primarily by instrumentationShaped primarily by instrumentation

Cleansing of the root canalCleansing of the root canal

ObjectivesObjectives Removal of organic debrisRemoval of organic debris Elimination of bacteriaElimination of bacteria

IrrigationIrrigation

An ideal irrigant:An ideal irrigant: Is nontoxic Is nontoxic Dissolves vital and necrotic tissueDissolves vital and necrotic tissue Is bactericidalIs bactericidal Lubricates the canalLubricates the canal Removes the smear layerRemoves the smear layer

Sodium hypochloriteSodium hypochlorite

Dissolves vital and necrotic Dissolves vital and necrotic tissuetissue

Is bactericidalIs bactericidal Lubricates the canalLubricates the canal

Sodium HypochloriteSodium Hypochlorite

Cannot be considered non-

toxic!!!

ProlubeProlube

EDTA and carbamide peroxide in a water soluble base

ProlubeProlube

Facilitates placement of fileFacilitates placement of file Entraps debrisEntraps debris Aids in removal of the smear layerAids in removal of the smear layer

EDTAEDTA

Chelating agentChelating agent Effectively removes smear layerEffectively removes smear layer

Shaping of the root canalShaping of the root canal

Canal shape – produced by Canal shape – produced by instrumentationinstrumentation

Objective is a smooth tapered Objective is a smooth tapered preparationpreparation

Shaping of the root canalShaping of the root canal

InstrumentsInstruments

Instruments differ according to:Instruments differ according to: MetalMetal TaperTaper Tip designTip design Cross sectional geometryCross sectional geometry Length of cutting bladesLength of cutting blades Sizing Sizing

MetalsMetals

Nickel titaniumNickel titanium Stainless steelStainless steel

Excellen flexibilityExcellen flexibility Less flexibleLess flexible

Conforms to canal Conforms to canal Straightens and Straightens and

curvature curvature transports canaltransports canal

Plastic deformationPlastic deformation Permanent Permanent deformationdeformation

MetalsMetals

Stainless steel files demonstrate permanent deformation

MetalsMetals

Nickel titanium files demonstrate plastic deformation

TaperTaper

DefinitionDefinition

Increase in diameter per unit lengthIncrease in diameter per unit length

What is Taper?What is Taper?

0.32 mm diameter increase

D16 D1

0.96 mm diameter increase

D16 D1

What is taper?What is taper?

TaperTaper

Taper of instruments in U of M file kitTaper of instruments in U of M file kit Stainless steel files – 0.02 taperStainless steel files – 0.02 taper OS – variable tapers ranging from 0.05 to OS – variable tapers ranging from 0.05 to

0.080.08 Series 29 rotary Profiles – 0.06 taperSeries 29 rotary Profiles – 0.06 taper NiTi hand files – 0.04 taperNiTi hand files – 0.04 taper

Tip DesignTip Design

Non-cutting tipNon-cutting tip Bullet nose (60 degree) tipBullet nose (60 degree) tip Smooth transition angle where tip Smooth transition angle where tip

meets flat radial landsmeets flat radial lands


Designed to follow a pilot holeDesigned to follow a pilot hole Guides instrument through canal Guides instrument through canal

during preparationduring preparation

Cross-sectional geometryCross-sectional geometry

Three radial landsThree radial lands Each contains bidirectional cutting Each contains bidirectional cutting

edgesedges Keep instrument centered in the Keep instrument centered in the

canalcanal Cutting edges scrape dentinCutting edges scrape dentin

Cross sectional geometryCross sectional geometry


•• NotNotSelfSelf--ThreadingThreading

•• Gentle Planing Gentle Planing ActionAction


Radial lands separated by three u-Radial lands separated by three u-shaped flutesshaped flutes

Provide space for accumulation of Provide space for accumulation of debrisdebris

Moves debris out of canal Moves debris out of canal

Length of cutting bladeLength of cutting blade

Traditionally 16 mmTraditionally 16 mm Orifice shapers – 10 mmOrifice shapers – 10 mm

Sizing of instrumentsSizing of instruments

ISO sizesISO sizes Number refers to tip diameter in Number refers to tip diameter in

tenths of mmtenths of mm The tip diameter increases by 0.05 The tip diameter increases by 0.05

mm from sizes 10 to 60, then by mm from sizes 10 to 60, then by 0.10 mm0.10 mm


% % increase in diameter from #10 increase in diameter from #10 to #15 file is 50%to #15 file is 50%

Difference between #55 and #60 Difference between #55 and #60 is only 9%is only 9%


Series 29Series 29 Progressive 29% increase in tip Progressive 29% increase in tip

diameter diameter Instruments are better spacedInstruments are better spaced More instruments in smaller sizes More instruments in smaller sizes

and fewer large instrumentsand fewer large instruments

Crown Down TechniqueCrown Down Technique

The coronal portion is prepared The coronal portion is prepared before the apical portionbefore the apical portion

Follows medical principle of Follows medical principle of cleansing before probing a woundcleansing before probing a wound


Eliminates constrictions in the Eliminates constrictions in the coronal regioncoronal region

Reduces effect of canal curvatureReduces effect of canal curvature Improves tactile awareness during Improves tactile awareness during

apical preparationapical preparation


Allows more effective irrigationAllows more effective irrigation Removes majority of tissue and Removes majority of tissue and

microbes before apical third is microbes before apical third is approachedapproached

Reduces change in working length Reduces change in working length during apical preparationduring apical preparation


Coronal thirdCoronal third Orifice shapersOrifice shapers Middle thirdMiddle third0.06 taper rotary Profiles0.06 taper rotary Profiles Apical thirdApical third 0.04 taper hand Profiles0.04 taper hand Profiles

Clinical ProcedureClinical Procedure Estimate working lengthEstimate working length Parallel radiographParallel radiograph Estimated working length is the distance Estimated working length is the distance

from the reference point to the from the reference point to the radiographic apexradiographic apex

Parallel RadiographParallel Radiograph

Clinical ProcedureClinical Procedure

Establish straight line access to Establish straight line access to apical thirdapical third


Explore canal patencyExplore canal patency Ensure that canal is negotiable to Ensure that canal is negotiable to

radiographic apexradiographic apex Small file – #10 K-fileSmall file – #10 K-file May need to precurve these SS filesMay need to precurve these SS files


Files used in a push/pull or Files used in a push/pull or quarter turn pull motionquarter turn pull motion

Never rotate these files Never rotate these files through 360 degreesthrough 360 degrees


Estimate canal sizeEstimate canal size Radiographic appearanceRadiographic appearance Crown/root morphologyCrown/root morphology Standardized tablesStandardized tables

Estimation of canal sizeEstimation of canal size

Estimation of canal sizeEstimation of canal size

See Table in manual


Actual WL determinationActual WL determinationPreparation should terminate atPreparation should terminate at Apical constrictionApical constriction 1 mm short of radiographic apex1 mm short of radiographic apex

Clinical TechniqueClinical Technique

Actual WL determinationActual WL determination RadiographRadiograph Apex locatorApex locator


Actual Working Length Determination


Apex LocatorApex Locator


Crown down cleaning and shaping of Crown down cleaning and shaping of canalscanals


This technique applies only to teeth This technique applies only to teeth ranging from 18 – 23 mm in lengthranging from 18 – 23 mm in length

Coronal third measurement is WL minus 8 Coronal third measurement is WL minus 8 mmmm

Middle third measurement is WL minus 4 Middle third measurement is WL minus 4 mmmm

Apical third measurement is WLApical third measurement is WL

Preparation of the coronal thirdPreparation of the coronal third

Coronal third measurement is working length minus Coronal third measurement is working length minus 8 mm8 mm

Prepared using Profile orifice shapersPrepared using Profile orifice shapers


Profile orifice shapersProfile orifice shapers In sequence larger to smallerIn sequence larger to smaller

Preparation of coronal thirdPreparation of coronal third

Measure WL minus 8 mm on largest OSMeasure WL minus 8 mm on largest OS Lubricate the canal with ProlubeLubricate the canal with Prolube


Rotate OS at 300 rpmRotate OS at 300 rpm

Note: Orifice shaper should be rotating at Note: Orifice shaper should be rotating at 300 rpm before it is placed in the canal300 rpm before it is placed in the canal

Advance the OS in 1 mm incrementsAdvance the OS in 1 mm increments When resistance is encountered retract When resistance is encountered retract

OS while still rotating OS while still rotating Never force any instrument apicallyNever force any instrument apically


This OS will not extend to WL minus 8 mmThis OS will not extend to WL minus 8 mm Irrigate copiouslyIrrigate copiously

IrrigationIrrigation


Move to next smallest OSMove to next smallest OSThis will extend further than previous instrument This will extend further than previous instrument

Repeat the steps described for largest OSRepeat the steps described for largest OS Move to next smallest OSMove to next smallest OS Continue this sequence until working length Continue this sequence until working length

minus 8 mm is reachedminus 8 mm is reached


Return to largest OSReturn to largest OS This will now extend further into This will now extend further into

the canal than it did previouslythe canal than it did previously Repeat this sequence until this Repeat this sequence until this

(the largest) OS reaches WL minus (the largest) OS reaches WL minus 8 mm8 mm


Never force any instrument apicallyNever force any instrument apically Irrigate after every instrumentIrrigate after every instrument Use copious amounts of ProlubeUse copious amounts of Prolube

Preparation of middle thirdPreparation of middle third

Middle third measurement is WL Middle third measurement is WL minus 4 mmminus 4 mm

Prepared using 0.06 taper Series Prepared using 0.06 taper Series 29 rotary Profiles in sequence 29 rotary Profiles in sequence larger to smallerlarger to smaller


Prepared with 0.06 Series 29 NiTi rotary Profiles


Measure working length minus 4 mm Measure working length minus 4 mm on the largest 0.06 taper series 29 on the largest 0.06 taper series 29 rotary filerotary file

Set green rubber stop at that lengthSet green rubber stop at that length Lubricate the canal with ProlubeLubricate the canal with Prolube


Rotate at 300 rpmRotate at 300 rpm

File must be rotating at 300 rpm before it File must be rotating at 300 rpm before it is placed in canalis placed in canal

Advance file in 1 mm incrementsAdvance file in 1 mm increments When resistance is encountered When resistance is encountered

retract file while still rotatingretract file while still rotating Copious irrigation with NaOClCopious irrigation with NaOCl

Preparation of the apical thirdPreparation of the apical third

Prepare to actual working lengthPrepare to actual working length Use 0.04 taper NiTi hand files in Use 0.04 taper NiTi hand files in

sequence smaller to largersequence smaller to larger

Preparation of apical thirdPreparation of apical third


Measure working length on #15 fileMeasure working length on #15 file Set rubber stop at that lengthSet rubber stop at that length Lubricate the canal with ProlubeLubricate the canal with Prolube


Advance size 15 file to working Advance size 15 file to working lengthlength

Rotate file through 360 degreesRotate file through 360 degrees Irrigate copiously with NaOCl Irrigate copiously with NaOCl

after each fileafter each file

Preparation of the apical thirdPreparation of the apical third

Advance size 20 file to working Advance size 20 file to working lengthlength

Continue through sequence, Continue through sequence, seating each file to working lengthseating each file to working length


The largest file that extends to working The largest file that extends to working length is the Master Apical file (MAF)length is the Master Apical file (MAF)

For large canals – minimum MAF #40 - 50For large canals – minimum MAF #40 - 50 For small canals – minimum MAF #35 - 40For small canals – minimum MAF #35 - 40

Master Apical FileMaster Apical File

Take a radiograph with MAF in place. Take a radiograph with MAF in place. This confirms:This confirms:• LengthLength• PlacementPlacement

Mission accomplishedMission accomplished

Smooth tapered preparationSmooth tapered preparation

cleaning and shaping of the root canal system edit by hou tiezhou 02988088507

Documents

taper slide

root canal slide

instrumentation slide

tip design slide

dentin slide

mind slide

smear layer slide

root canal canal shape