Instruments For Canal Preparation - Kampus Kesihatan SAMAAN151006/ProTaperManual.pdf · Instruments...

Instruments For Canal Preparation

Endodontic Week For 5th Year StudentsUniversiti Sains Malaysia

10-14 September, 2007

Dr. Sam’an Masudi

Introduction

Success and failures of RCTObjectives of canal preparationHistory of endodontic filesDesign - Conventional file and greater taper filesTechniques used:

Crown Down concept 2 Techniques - Modified Double Flare & Hand Protaper Preparation

Success and Failure

Depends on thorough cleaning of the canalHow?

IsolationChemomechanical debridement -cleaning and shapingGood obturationCoronal seal

Success Case

46

Pre - operative

46

2 years review

Failure

Pre - operative

36

1 year review

36

Objective of Root Canal Preparation1. Eliminate microorganisms.2. Remove remaining pulp tissues.3. Remove debris.4. Shape the root canal system so that it may

be obturated. [1,2,3 are Cleaning process][4 is Shaping process]

Debridement of the root canal created during cleaning and shaping process.Irrigation and disinfection are integral parts of debridement

The principle of shaping

Develop a continuously tapering funnel from the apex to coronal orifice.Maintain the original shape of the canalMaintain the apical foramen in its original positionKeep the apical opening as small as possible.

Root Canal Preparation

2 approaches1) prepare the coronal section of the canal

system 1st with large instruments and progress towards the apex [Crown Down]

2) start at the apex with fine instruments and progress back towards the cervical orifice with large instruments [Step Back preparation]

RC Preparation (Cont’d)

Advantages of (1) method:1. Reduce the possibility of microbial

inoculation into the apical portion of the canal and then into the periapicaltissues

2. Early coronal flaring allows better penetration of irrigation solution

3. Early coronal flaring gives better access to the apical part of root canal

Techniques

1. Step-back2. Step-down3. Double-flare4. Crown down pressure-less5. Mechanized techniques of root canal

preparation(e.g. rotary technique)

Objectives of Canal Prep :

Aim :To clean and eliminate microorganisms (??), remove infected pulp tissue and debris.

To shape the pulp space so that it takes on a tapering form, being widest coronally and narrowest apically

Access cavityThe most important phase of the technical aspect of root canal treatmentWithout adequate access preparation instrument preparation and material placement would be very tedious and often result in despair and frustration.

Most indefinitely will affect the outcome and success rate of the treatment

Lets look at some of these access cavities

Why access so crucialAccess

Most important especially when using rotary instrument*Curved canal can be

Naturally occurringArtificially created via poor access

When an instrument bends in the canal the metal experiences compressing forces on the inner curvature and stretching forces on the outer curvature

How much can we clean the canal?

Problems in cleaning canal :

Single rooted tooth

Problems in cleaning canal :

Multi-rooted/complex root canal system

Chemomechanical Debridement

Chemical Irrigant ProtocolIrrigant

AntibacterialNaOCl (2.5 - 5%) as main irrigant. Alternative?

Smear layer removalEDTA solution (17%) as final rinseMTAD

Lubricant - Glyde, RC Prep

Effects of irrigations

Mechanical ShapingWhat are we trying to achieve ?

A tapering conical shape from the canal orifice to the apexOriginal shape of the canal is preservedOriginal location and size of the apical foramen is preserved

Endodontic Files(Manual Instrumentation)

Types of Hand Files

Conventional Files Greater Taper FilesISO sized filesMade from stainless steel/NitiDesign

K-FileFlexofileHeadstrom fileReamer

Non standardisedfilesMade from NiTi

DesignGT filesProtaper files

Conventional Files

Conventional Files

Standard file - follow the ISO numberingSize of the file represents the diameter at the tipConstant taper : 0.02 mm per mm lengthLength of blade : 16 mmLength of file : comes in 21mm, 25mm, 31mm

Design:K-Files/Flexofiles

- Made by twisting grounded wire

- Can be square or triangular in cross section

- Sharp flutes

- Non-cutting tip

- Flexible esp if the cross section is triangular. Therefore it will follow the canal curvature

Design: Headstrom File

Made by machining rod wire to make the flutesSharp and aggressiveCut dentine by up-down movement in canalSmaller size - tend to break easily

How to use K-file ?

Technique of Canal Preparation

Modified Double Flare Technique

Canal Preparation

Traditional concept:Apical coronal preparationCanal preparation starts from the apex to the coronal part

Current concept:Coronal apical preparationPreparation of the coronal part first before preparation of the apical part

Crown-down Approach

Using a combination of hand files and rotary (GG burs) Sequence :

Access cavity - straight line accessCoronal Flaring WL determinationApical Preparation

Canal Preparation

Crown-down ApproachAdvantages :

Removal of bulk microorganisms at the coronal third to prevent accidental pushing the apical partReduces the hydrostatic pressure that can occur in the canal Give better access to the apical part of the root canalAllows better penetration of the irrigantsolutionMinimise loss of working length

Modified Double Flare:

Stages:

• Coronal Flare

• Working length

• Apical preparation (Step- back)

Access Cavity

Straight Line Access

Coronal Flare

2/3 WL

EWL

How big is your coronal flaring ?

• Enough for irrigation needle to enter 2/3 into the

Coronal Flaring

Coronal Flaring

What if the coronal part is already big ?

Which tooth ?Anterior central incisorsCaninesPremolars (lower 1st and upper 2nd)

Working Length

Estimation of working lengthUse apex locator

Confirm with radiograph

Apical Preparation

Enlarge the diameter of the apical partAim :

To enlarge enough to allow penetration of needle and irrigantTo remove infected tissuesTo allow good exchange of irrigantTo determine the apical stop

Apical Preparation

2/3

WL

Gauge

IAS

IAS MAF

Step Back

Apical Preparation

Step-back technique - to form apical taper

Technique - Step Back

2/3 WL

WL

MAF

Shape of Final Preparation

Continuous taperOriginal curvature maintainedOriginal size and position of apical foramen maintainedApex remained patent

Common Error

Greater Taper Files

Designed based on crown-down concept

Nickel Titanium

Advantages:

Flexibility

Strength

Shape memory

Anti-corrosive

Does not weaken following sterilization

Earlier File

GT files

SX

S1S2 F1

F2F3

FINISHERS F1, F2, F3SHAPERS SX, S1, S2

PROTAPER FOR HAND USE

Protaper Files

Initially introduced as rotary files onlyBased on crown down conceptUsing a sequence of 6 files

S1, Sx and S2 --> coronal flareF1/F2/F3 --> apical preparation

Taper of file

-0.80

-0.70

-0.60

-0.50

-0.40

-0.30

-0.20

-0.100.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Root canal length [mm]

S 1

S 2F 1F 3 F 2

SX

Multiple & Progressive Taper

Benefits of design:Increased flexibilityEach instrument produces its own 'crown down effect' as larger tapers make way for smaller tapers･Protaper files engage a smaller area of dentine reducing torsional loads and file fatigueThe cross section reduces the contact area between file and dentinIncreased cutting efficiency without 'screwing' Canal shapes which are uniformly tapered over length

ProTaper New Shaping File S2

-0.80

-0.70

-0.60

-0.50

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Root canal length [mm]

New sequence

Current sequence

New ProTaper S2Change : slight modification of tapers along the fluteResult : work is better balanced between S1 – S2 and F1Benefit : transition from S2 to F1 is smoother

S1 out shape

S2 outshape

F1 out shape

Modification of Taper For S2

Cross Section

Triangular Convex

Tip of Finishing Files

Earlier - modified active tip

Removal of Transition Angle Result : tip is now more

rounded – Safer, less transportation

Blade Design

Variable Helical Flute Angle

Overall Design of Protaper

Nickel-TitaniumMultiple & Progressive TaperTriangular Convex X- SectionModified Rounded TipVariable Helical Flute Angle

Improvements of Design

X-section of F3Introduction of F4 & F5

ProTaper New Finishing File F3

New Cross Section

New ProTaper F3Changes : cross section has been reduced by

making grooves along the flute Result : improved flexibility – reduced stiffnessBenefit : better respect the canal path

ProTaper F4


Tip Size : 040

Taper (first mm) : 6%

Easy to recognize :

Black handle + marking F4 on the top for the manual version, double black rings for the rotary version

Feature

Lightened Cross Section

Large Tip Size

Benefits

Improved flexibility

Respect the root canal path

ProTaper F5


Tip Size : 050

Taper (first mm) : 5%

Easy to recognize :

Yellow handle + marking F5 on the top for the manual version, double yellow rings for the rotary version

Feature

Lightened Cross Section

Large Tip Size

Benefits

Improved flexibility

Respect the root canal path

Hand Protaper- Clinical Procedures

Files Sequence:

ProTaper for Hand UseClinical Procedures

Explore canal w/ #10 hand file

Explore Canal w/ #10 hand file

Negotiate to #15 w/ hand file


Explore Canal w/ #10 hand fileNegotiate to #15 w/ hand file

Coronal Flaring w/ S1Insert file with slight apical pressure until resistance

½ turn clockwise

½ turn anticlockwise

Withdraw

Clean


S1

Insert w/ slight apical pressure until resistance

S1

¼ to ½ turn clockwise

S1

¼ to ½ turn anticlockwise

=S1

Withdraw & clean file

Explore Canal w/ #10 hand fileNegotiate to #15 w/ hand fileCoronal Flaring w/ S1Coronal Flaring w/ SX (optional) using same motion

May replace w/ GG Drill


SX

2

3

4

1


Coronal Flaring (S1, SX)

Working Length Determination





Coronal 1/3 Preparation w/ S1 again (up to full working length) using same motion





Coronal 1/3 Preparation w/ S1

Middle 1/3 Preparation w/ S2 (up to full working length) using same motion


S1,S2 TO WORKING LENGTH





Middle 1/3 Preparation w/ S2

Apical 1/3 Preparation w/ F1 & F2, using the same motion


F1, F2 TO WORKING LENGTH







Apical 1/3 Preparation w/ F1 & F2

Gauge w/ #25 hand file






Apical 1/3 Preparation (F1 F2)

For larger canals, continue apical prep w/ F3, using also the same motion


F3 TO WORKING LENGTH







Apical 1/3 Preparation (F1 F2 F3)

Gauge w/ #30 hand file

ProTaper for Hand Use Clinical Sequence

a. Establish straight line accessb. Explore canal w/ #10, then #15c. Flare coronal w/ S1, followed

by SX if necessary (penetration ≤ #15)

d. Measure/confirm working length w/ #15

e. Use S1 to lengthf. Use S2 to lengthg. Use F1 to lengthh. Use F2 to length

(recommended min.), followed by apical gauging

i. Use F3 to length (optional for larger canals)

Cut by rotating clockwise with sufficient apical pressure until engages the dentin. Rotate counter-clockwise to disengage, remove and wipe the file clean. Repeat rotating motions until desired length is achieved

ProTaper for Hand Use User Guidelines

a. Prepare straight line accessb. Use patency filesc. Check instruments before used. Use files in correct motione. Clean flutes and irrigate regularlyf. Use lubricants, e.g. Glyde

ComparisonProtaper Hand Files SS Files

Fewer instruments needed for preparation The canal can be prepared

with moderate speed ProTaper design increases

cutting efficiency Canal curvature is well

maintained

Consistent tapered preparation coronal to apical with minimal foramen enlargement

Many instruments are needed for preparation Preparation is slow

Cutting efficiency poor due to poor designTransportation is very common

Tapered preparation always inconsistent with over enlargement apically highly probable

ComparisonProtaper Hand Files SS Files

Less debris is extruded apically

Can be used in abrupt curvature with prebentinstrument WHEN pathway established by hand SS files

Instrument separation is low due to good tactile feedback

Debris extrusion apically is high

Can be used in abrupt curvature but final preparation never smooth

Instrument separation has not been a historic problem

Questions ?

Instruments For Canal Preparation - Kampus Kesihatan SAMAAN151006/ProTaperManual.pdf · Instruments...

Documents

Transcript of Instruments For Canal Preparation - Kampus Kesihatan SAMAAN151006/ProTaperManual.pdf · Instruments...