cleaning and shaping of the root canal system edit by hou tiezhou 02988088507
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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
Tip DesignTip Design
Designed to follow a pilot holeDesigned to follow a pilot hole Guides instrument through canal Guides instrument through canal
during preparationduring preparation
Tip DesignTip Design
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
Cross sectional geometryCross sectional geometry
•• NotNotSelfSelf--ThreadingThreading
•• Gentle Planing Gentle Planing ActionAction
Cross sectional geometryCross sectional geometry
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
Sizing of instrumentsSizing of instruments
% % 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%
Sizing of instrumentsSizing of instruments
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
Crown Down TechniqueCrown Down Technique
Crown Down TechniqueCrown Down Technique
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
Crown Down TechniqueCrown Down Technique
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
Crown Down TechniqueCrown Down Technique
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
Clinical ProcedureClinical Procedure
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
Clinical ProcedureClinical Procedure
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
Clinical ProcedureClinical Procedure
Clinical ProcedureClinical Procedure
Clinical ProcedureClinical Procedure
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
Clinical ProcedureClinical Procedure
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
Clinical ProcedureClinical Procedure
Actual Working Length Determination
Clinical ProcedureClinical Procedure
Clinical ProcedureClinical Procedure
Apex LocatorApex Locator
Clinical ProcedureClinical Procedure
Crown down cleaning and shaping of Crown down cleaning and shaping of canalscanals
Clinical ProcedureClinical Procedure
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
Preparation of the coronal thirdPreparation of the coronal third
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
Preparation of coronal thirdPreparation of coronal third
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
Preparation of the coronal thirdPreparation of the coronal third
This OS will not extend to WL minus 8 mmThis OS will not extend to WL minus 8 mm Irrigate copiouslyIrrigate copiously
IrrigationIrrigation
Preparation of coronal thirdPreparation of coronal third
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
Preparation of coronal thirdPreparation of coronal third
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
Preparation of the coronal thirdPreparation of the coronal third
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 coronal thirdPreparation of coronal third
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
Preparation of middle thirdPreparation of middle third
Prepared with 0.06 Series 29 NiTi rotary Profiles
Preparation of middle thirdPreparation of middle third
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
Preparation of middle thirdPreparation of middle third
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 middle thirdPreparation of middle third
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
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
Preparation of apical thirdPreparation of apical third
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
Preparation of apical thirdPreparation of apical third
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
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