Cleaning and Shaping of the Root Canal System. Part IIEdit by Hou Tiezhou02988088507

Root Canal InstrumentationEstimate working lengthVerify canal patencyEstimate canal sizeEstablish actual working length

Root Canal InstrumentationCrown down preparationCoronal thirdMiddle thirdApical third

Armamentarium

Armamentarium

ArmamentariumStainless steel size 10 K-filesUsed to explore canal patencyFiling or quarter turn pull motion Do not rotate through 360 degrees

ArmamentariumStainless steel size 15 and 20 K filesUsed to establish actual working length

Armamentarium

ArmamentariumProfile orifice shapersUsed to prepare the coronal one third of the root canal

Profile Orifice Shapers

ArmamentariumProfile 0.06 taper rotary filesUsed to prepare the middle third

Armamentarium

ArmamentariumProfile 0.04 taper hand NiTi filesUsed to prepare the apical third of the root canal

Armamentarium

Estimated Working LengthEstimated working length is the distance from the reference point to the radiographic apex, as measured on a parallel preoperative radiograph

Estimated working lengthTake a pre-operative parallel radiographClinically, use a XCP film holder

Estimated working length Length from incisal edge to radiographic apexOnly an estimate because of radiograph distortion

Estimate canal sizeRadiographic appearanceCrown/root morphologyStandardized sizes (See table in manual)

Estimate canal size

Explore Canal PatencyEnsure that canal can be negotiated to radiographic apexSelect #10 K filePrecurve file if necessary

Explore Canal Patency

Explore Canal Patency

Establish Actual Working lengthInstrumentation should terminate at:The apical constriction1 mm short of radiographic apexActual WL = Estimated WL 1 mm

Establish actual working lengthWL can be established using:RadiographsApex locator

Establish Actual Working Length

Establish Actual Working Length

Establish Actual Working Length

Establish Actual Working Length

Crown Down Preparation

Crown Down Preparation

Crown-down preparationPlastic incisor with transparent root

Crown-down preparationPlace SS K file into canal until the tip is just visible at the apex

Actual Working LengthRemove file from canalSubtract 1 mmThis is the actual working lengthIn this case the WL is 20 mm

Actual Working Length

Preparation of Coronal Third

Preparation of Coronal ThirdThe coronal third measurement is WL minus 8 mm, that is 12 mmProfile OS do not have rubber stops however the cutting flutes measure 10 mmThe goal is to work the largest OS to 12 mm

Preparation of coronal third

Preparation of coronal third

Preparation of the coronal thirdRotate OS at 300 rpmNote: Orifice shaper should be rotating at 300 rpm before it is placed in the canalAdvance the OS in 1 mm incrementsWhen resistance is encountered retract OS while still rotating Never force any instrument apically

Preparation of coronal thirdBlue (#60) OS extends to approx. 9 mm

Preparation of coronal third

Preparation of coronal third

Preparation of coronal thirdGold (#50) OS reaches 12 mm

Preparation of coronal thirdProgress from larger to smaller orifice shaperEach smaller OS will extend further into canalRepeat the sequence until the largest OS extends to 12 mm

Preparation of coronal thirdBlue (#60) OS extend to WL 8 mm = 12 mm

Preparation of Middle ThirdProfile 0.06 taper series 29 rotary files

Preparation of Middle ThirdProfile 0.06 taper series 29 rotary filesThe middle third measurement is WL minus 4 mm, that is 16 mmThe aim is to work the brown (#7) file to 16 mm

Preparation of Middle ThirdProceed from larger to smaller fileEach smaller file will extend further into the canalRepeat the sequence until the largest file extends to 16 mm

Preparation of middle third

Preparation of middle third

Preparation of middle third

Preparation of middle third

Preparation of middle third

Preparation of middle third

Preparation of middle third

Preparation of middle third

Preparation of middle third

Preparation of middle third

Preparation of apical thirdProfile 0.04 taper nickel titanium hand files

Preparation of apical thirdProfile 0.04 taper nickel titanium hand filesThe measurement is the full working length, that is 20 mm

Preparation of apical thirdMeasure working length on #15 fileSet rubber stop at that lengthLubricate the canal with Prolube

Preparation of apical thirdAdvance size 15 file to working lengthRotate file through 360 degreesIrrigate copiously with NaOCl after each file

Preparation of the apical thirdAdvance size 20 file to working lengthContinue through sequence, seating each file to working length

Preparation of apical thirdProgress from smaller to larger filesEach file is fully seated at working lengthSmall canals prepared to a minimum of ISO 35 or 40Large canals prepared to a minimum of ISO 40 50

Preparation of apical third

Preparation of apical third

Preparation of apical third

Preparation of apical third

Preparation of apical third

Preparation of apical third

Preparation of apical third

Preparation of apical third

Preparation of apical third

Preparation of apical third

Preparation of apical third

Preparation of apical third

File kit on completion of instrumentation

Master Apical File (MAF)The largest file that extends to working lengthMAF film is exposed to confirm length and placement

Master Apical FileFor large canals minimum MAF #40 - 50For small canals minimum MAF #35 - 40

Master Apical FileTake a radiograph with MAF in place. This confirms:LengthPlacement

Mission Accomplished