Cleaning and Shaping of the Root Canal System. Part II

Edit by Hou Tiezhou02988088507

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 rpmNote: 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

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