Cleaning and Shaping of the Root Canal System. Part II Edit by Hou Tiezhou 02988088507

Root Canal Instrumentation Estimate working length Verify canal patency Estimate canal size Establish actual working length

Root Canal Instrumentation Crown down preparation Coronal third Middle third Apical third

Armamentarium

Armamentarium

Armamentarium Stainless steel size 10 K-files Used to explore canal patency Filing or quarter turn pull motion Do not rotate through 360 degrees

Armamentarium Stainless steel size 15 and 20 K files Used to establish actual working length

Armamentarium

Armamentarium Profile orifice shapers Used to prepare the coronal one third of the root canal

Profile Orifice Shapers

Armamentarium Profile 0.06 taper rotary files Used to prepare the middle third

Armamentarium

Armamentarium Profile 0.04 taper hand NiTi files Used to prepare the apical third of the root canal

Armamentarium

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

Estimated working length Take a pre-operative parallel radiograph Clinically, use a XCP film holder

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

Estimate canal size Radiographic appearance Crown/root morphology Standardized sizes (See table in manual)

Estimate canal size

Explore Canal Patency Ensure that canal can be negotiated to radiographic apex Select #10 K file Precurve file if necessary

Explore Canal Patency

Explore Canal Patency

Establish Actual Working length Instrumentation should terminate at: The apical constriction 1 mm short of radiographic apex Actual WL = Estimated WL – 1 mm

Establish actual working length WL can be established using: Radiographs Apex 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 preparation Plastic incisor with transparent root

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

Actual Working Length Remove file from canal Subtract 1 mm This is the actual working length In this case the WL is 20 mm

Actual Working Length

Preparation of Coronal Third

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

Preparation of coronal third

Preparation of coronal third

Preparation of the coronal third Rotate OS at 300 rpm Note: Orifice shaper should be rotating at 300 rpm before it is placed in the canal Advance the OS in 1 mm increments When resistance is encountered retract OS while still rotating Never force any instrument apically

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

Preparation of coronal third Irrigation! Irrigation! Irrigation!

Preparation of coronal third

Preparation of coronal third Gold (#50) OS reaches 12 mm

Preparation of coronal third Progress from larger to smaller orifice shaper Each smaller OS will extend further into canal Repeat the sequence until the largest OS extends to 12 mm

Preparation of coronal third Blue (#60) OS extend to WL – 8 mm = 12 mm

Preparation of Middle Third Profile 0.06 taper series 29 rotary files

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

Preparation of Middle Third Proceed from larger to smaller file Each smaller file will extend further into the canal Repeat 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 third Profile 0.04 taper nickel titanium hand files

Preparation of apical third Profile 0.04 taper nickel titanium hand files The measurement is the full working length, that is 20 mm

Preparation of apical third Measure working length on #15 file Set rubber stop at that length Lubricate the canal with Prolube

Preparation of apical third Advance size 15 file to working length Rotate file through 360 degrees Irrigate copiously with NaOCl after each file

Preparation of the apical third Advance size 20 file to working length Continue through sequence, seating each file to working length

Preparation of apical third Progress from smaller to larger files Each file is fully seated at working length Small canals prepared to a minimum of ISO 35 or 40 Large 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 length MAF film is exposed to confirm length and placement

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

Master Apical File Take a radiograph with MAF in place. This confirms: Length Placement

Mission Accomplished