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Masters In General Dental

Practice.

Endodontology Module

Rotary Instrumentation Mike Waplington

Specialist in Endodontics

Underlying Principles

Managing a microbiological problem

Aim treatment at removal and destruction of

bacteria

Root canal systems frequently have complex

anatomy

Bacteria enter the root canal at the coronal end

Antiseptic Principles

Mechanical debridement of pulp space

Removal of infected dentine

Use of antimicrobial agents

Complex Root Canal Anatomy

Crown Down

Instrumentation

Works with any instrument systems

Cleaning and Shaping

Cleaning removes pulp remnants, bacteria and infected dentine Shaping allows placement of irrigant and filling material

Both objectives can be achieved simultaneously using instrumentation and irrigation

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Schilder’s four mechanical objectives:

CTP OAM PFM FSP

Mechanical Preparation

Apical Preparation First

Restrictive dentine not removed Coronal flute binding Precurved files straighten

Non optimal irrigation

Canal blockage POE’s blocked before irrigants get there

Canal Preparation Sequence

Explore coronal 2/3’s

Prepare coronal 2/3’s

Explore apical 1/3

Establish patency/WL

Prepare apical 1/3

Lubricants

Initial irrigant

Keep debris in

suspension

Emulsify pulp stump in

vital cases

Cleaner canal?

Irrigation

Liquid irrigants do not reach apical region

until it has been opened

Hypochlorite is the preferred irrigant

1%-5% (volume v concentration)

Bend irrigation needle to make it easier to

insert

Safe Irrigation Never bind irrigation

needle

Never inject solution

Always irrigate very

slowly

27g = 0.40mm

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Rotary NiTi

Profile .06

System GT

Protaper

( TF, GTX )

Scout the canal with hand file first

Rotary Usage Big to small

Larger taper to smaller

taper

Crown down

preparation

Electric motor

Enlargement

not

Negotiation

Rotary NiTi Technique

Gear reduction handpiece @ 150-500rpm Use crown-down Large size to small size Minimal apical pressure Lubricate / irrigate Only use for 4 secs per file Clean instruments Single use files

ProFile .06’s

Size Taper D0 D16

20 .06 20 1.16

25 .06 25 1.21

30 .06 30 1.26

35 .06 35 1.31

Identical taper/differing tip size

Profile .06 File Characteristics

Radial Lands

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ProFile .06

.04, .06, .08, .10

All 20 at tip. 30 and 40 available Use larger taper to smaller taper. 300rpm

System GT

Same tip size/differing taper

Protaper Shaper Files

S1- D0 0.185mm

D14 1.2mm

S2- D0 0.20mm

D14 1.1mm

SX- D0 0.19mm

D14 1.2mm

S1 S2 SX

Variable taper and tip size

The importance of good straight line

access

The importance of good straight line

access Coronal 2/3’s opened

Provides reservoir for irrigant

Removes restrictive dentine

Files drop easily into canal

Now ready to explore apical 1/3

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Explore Apical 1/3

Patency File

Place 10F just

through foramen

Do not use

vigorously

Working Length

Measurement Get an Apex Locator

Completion of Apical 1/3

Hand vs Rotary NiTi Explore with hand file first

If anatomically complex: Hand

Cannot move 15 to length easily

If straightforward use rotary shaping files

Can easily move 15 to length over apical 3-4mm’s

Take care with certain canal shapes

Waves of Shaping

Do not Force Files

ProFile .06’s

Recapitulate

Larger files make space for apical progression of smaller ones

Thus on future recapitulations each file goes deeper

Continue till 20/.06 or 25/.06 at length

Protaper Finishing Files

F1- D0 0.20mm

.07

F2- D0 0.25mm

.08

F3- D0 0.30mm

.09

F1 F2 F3

300rpm. Work 1mm short of terminus

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Protaper F2 Serial Step Back

Step Back Check with Hand

Instruments Is there adequate apical

resistance form

Ensure each larger

consecutive instrument

uniformly backs out of canal

Look for instrument that

binds just short of terminus

and step back from that one

Hybrid Techniques

Combination of ProFiles and System GT

Combination of Gates and ProFiles

Combination of hand files and System GT

Combination of Protaper and System GT

ProSystem GT

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Protaper/GT Hybrid Protaper/ProSystem GT Hybrid

Rotary NiTi Advantages Blockage minimised especially with crown down

preparation

Transfer of central axis minimised

Increased success?

Using rotary has improved my endo

Rotary Limitations

File fracture

Take care with

certain canal types

Avoiding Rotary NiTi Fracture

Use a lubricant

Approach working length in small increments

Discard if any distortion of flutes

Open canal by hand to make way for rotary

Twisted Files (TF).

Sybron

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Twisted Design Ground file

TF is twisted to maintain grain structure

May need to use

precurved file to

instrument one

branch of division

Canals that split

Canals that Join Take care with rotary in

view of sudden stress

changes

Check whether join with

hand files

Curved Canals Moderate curvatures can

be prepared safely with

rotary nickel titanium

files

Do not use round severe

curves

Dentsply Pathfiles Self Adjusting File SAF. (Schein)

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Wave One (Dentsply). Use glidepath

Reciproc (VDW). No glidepath, single file

Reciprocating systems G.Yared. IEJ 2008

Hands-on