BDS(NBI), CIBRD(KASADA), MDSc-Endo(Mal), BDS(NBI), CIBRD(KASADA), MDSc-Endo(Mal), Cert. In Oral Implantology (Mal)Cert. In Oral Implantology (Mal)

SPECIALIST ENDODONTIST,IMPLANT SPECIALIST ENDODONTIST,IMPLANT PRACTITIONER AND LECTURERPRACTITIONER AND LECTURER

Dept of Conservative DentistryDept of Conservative Dentistry

University of NairobiUniversity of Nairobi

Practice limited to Endodontics and implantologyPractice limited to Endodontics and implantology

E-Mail: tomdienya@uonbi.ac.ke or E-Mail: tomdienya@uonbi.ac.ke or tomdienya@yahoo.comtomdienya@yahoo.com

Introduction and Lit reviewIntroduction and Lit review The goal of endodontic therapy is the prevention The goal of endodontic therapy is the prevention

and/or elimination of pathosis of endodontic originand/or elimination of pathosis of endodontic origin

Correct diagnosisCorrect diagnosis

Complete obturationComplete obturation Cleaning and Debridement

SUCCESFULL RCT

(European Society of Endodontology Consensus, 1994, Omer (European Society of Endodontology Consensus, 1994, Omer et alet al., 2004, , FDI World ., 2004, , FDI World Dental Press, 2005 ).Dental Press, 2005 ).

Introduction and Lit Review cont..Introduction and Lit Review cont..

Inadequate understanding Of Root Canal SystemsDetailed Knowledge of ROOT

CANAL SYSTEM

Improper shapingAndInadequate Cleaning

SUCCESSFUL ROOT CANAL

Omer et al.,2004,Mikrogeorgis et al.,1999,Al-Nazhan,2007

Poor Obturation

TreatmentFailure

Carrotte,2004

INTRODUCTION CONT..INTRODUCTION CONT..

A tooth with a straight root and a A tooth with a straight root and a straight root canal is an exception straight root canal is an exception rather than being normal because rather than being normal because most teeth show some curvature of most teeth show some curvature of the canal the canal (weinne,scheinder,kyomin(weinne,scheinder,kyomin).).

Tomes, in 1848, called such Tomes, in 1848, called such curvatures as dilacerationscurvatures as dilacerations

Dilaceration:Dilaceration:DefinationDefination

It refers to an angulation or a bend It refers to an angulation or a bend or a curve in the root or crown of or a curve in the root or crown of formed tooth or a deviation or in the formed tooth or a deviation or in the linear relationship of a crown of a linear relationship of a crown of a tooth to its root.tooth to its root.

EpidemiologyEpidemiologyIn most studies,prevalence of In most studies,prevalence of

curvature ranged between 80 to curvature ranged between 80 to 100%. Dienya et al 2009 in a study 100%. Dienya et al 2009 in a study of 400 maxillary and mandibular 1of 400 maxillary and mandibular 1stst molars in a Kenyan population got molars in a Kenyan population got 91% curvature.91% curvature.

Dr Schaffer in Germany examined Dr Schaffer in Germany examined 1163 root canals and found that 980 1163 root canals and found that 980 (84%) were curved and 65% showed (84%) were curved and 65% showed an angle > 27 degrees with radii < an angle > 27 degrees with radii < 40 mm. 40 mm.

CAUSECAUSE

The condition is thought to be The condition is thought to be due to trauma during the period due to trauma during the period in which tooth is forming. in which tooth is forming.

The result is that the position of The result is that the position of the calcified portion of the tooth the calcified portion of the tooth is changed and the remainder of is changed and the remainder of the tooth is formed at an anglethe tooth is formed at an angle

Types of curvaturesTypes of curvatures

Curved canals can beCurved canals can be:: Gradual curvature of the canals Gradual curvature of the canals

in the coronal,middle or apical in the coronal,middle or apical third;third;

Acute curvature in the apical Acute curvature in the apical third;third;

Curvature throughout the canal;Curvature throughout the canal; S-shaped root canalS-shaped root canal..

Mandibular 1Mandibular 1stst molar with GRADUAL molar with GRADUAL distal curvature of the mesial rootdistal curvature of the mesial root

Maxillary molar with the DB root showing Maxillary molar with the DB root showing ACUTE curvature in the apical thirdACUTE curvature in the apical third

Buccal curvature at the tip of a palatal root

Mandibular 1st molar with an S-curvature of the D root

Combination of S-shaped canals and gradual shape

THE STAIR CASE CURVE

THE DECEIVING CURVE ---distal root curves lingually

THE CONSEQUENCESTHE CONSEQUENCES

1) EXCESSIVE FLARING

2) LEDGING

3) APICAL TRANSPORTATION

4) APICAL PERFORATION

SHORT OBTURATION- due to SHORT OBTURATION- due to inability to negotiate curvatureinability to negotiate curvature

Common to all curvatures:Common to all curvatures:

• Instruments break Instruments break unexpectedlyunexpectedly

• Separated apical part Separated apical part is difficult to removeis difficult to remove

A Major Drawback !

A Major Drawback !

Instruments separation just at the beginning of the curve

Missed canal in maxillary 1Missed canal in maxillary 1stst molarsmolars

Note : Canal was missed probably due to it being hidden at the beginning of the curve

presence of lamina dura—indicates canal presence

painpain

ManagementManagement

Start with accurate diagnosisStart with accurate diagnosis

preoperative radiographs taken with parallelling technique with at least two different views-SLOB RULE:

UPPER TEETH-normal buccal view,then use rule MMMM

LOWER TEETH—normal buccal view then use the rule DMMD or use CBCT OR DIGITAL X-RAYS

Paralleling technique in the lower Paralleling technique in the lower jawjaw

Parallel periapicalsParallel periapicals

Root canal configurations obtained with Root canal configurations obtained with CBCTCBCT

Type I Type II Type IIIType IV

Type V Type VIAdditional

Canals 1

Additional canal

2

Additional Canal 3

Make a good access cavityMake a good access cavity

Pitfalls of inadequate accessPitfalls of inadequate access

Inadequate acess easily leads to ledging

Remnants of pulp roof removed by slow speed round bur

Straight line access achieved

Determine the DEGREE OF curvature

Before initiation of treatment, an estimate should be made as to the degree of curvature of canals by seeing the radiograph, probing OR schneiders method

The interior angle is formed by intersection of the straight line from the orifice through coronal portion of the root and another straight line from apex through apical portion of canal

Take an impression of the Take an impression of the canalcanal

S-shaped c-shaped

J--shapedMerging canals

USE CROWN DOWN USE CROWN DOWN TECHNIQUETECHNIQUE

Divide the root into threeDivide the root into three

Flare coronal one third and Flare coronal one third and open up orifice-use orifice open up orifice-use orifice

shapersshapers

Or 25/07 in mtwo system or sx in protaper system—Do not use gates glidden.

ENDOFLARE

1

Before ENDOFLARE® filing - Pronounced dentinal overhang

2

ENDOFLARE® filing

(penetration < coronal third)

3

After ENDOFLARE® filing - Elimination of the coronal strains

BEFORE

AFTERPr. CALAS

Working lengthWorking length

Working length-practical Working length-practical determinationdetermination

Use apex locatorsUse apex locators—such as raypex 6 —such as raypex 6 or vdwor vdw

motormotor

No direct measurements on fileNo direct measurements on file

Direct measurements are likely to introduce errors

MEASURE CURVATURE by MEASURE CURVATURE by tracingtracing

rulesrules R>160------stainless steel handfiles can be R>160------stainless steel handfiles can be

usedused R—140—160---consider precurving stainless R—140—160---consider precurving stainless

steel files or use rotarysteel files or use rotary R –100—140—rotary with initial glide R –100—140—rotary with initial glide

path;use highly flexible files with radial path;use highly flexible files with radial lands or use rotary in straight portion and lands or use rotary in straight portion and hand files apicallyhand files apically

R –90—100—niti hand files with high R –90—100—niti hand files with high flexibility; orifice shapers only coronallyflexibility; orifice shapers only coronally

R—90 or less—consider apicoectomy and R—90 or less—consider apicoectomy and reverse filling,aggressive use of hand nitireverse filling,aggressive use of hand niti

managementmanagementUSE OF HAND NITI FILES

Tedious..some files can break due to torsional stress

PRECURVING STAINLESS STEEL FILES

Crown Down TechniqueCrown Down Technique

Crown Down TechniqueCrown Down Technique

Coronal thirdCoronal third Orifice shapersOrifice shapers Middle thirdMiddle third0.06 taper rotary 0.06 taper rotary Apical thirdApical third 0.04 OR 0.02 taper hand or rotary0.04 OR 0.02 taper hand or rotary

FILES TO USE

Red sequenceHERO ShapersHERO Shapers

25 4% 30 4%

2/3 WL

WL +

WL

2/3 WL

WL

25 6%

+

Red sequence for average difficult cases

Yellow sequence

HERO ShaperHERO Shaper

HERO ShaperHERO Shaper

Yellow sequence

25 4% 30 4%

2/3 WL

WL +

WL

2/3 WL

WL

20 4%

+

20 6%

WL +

Yellow sequence for difficult cases

Preparation of coronal thirdPreparation of coronal third

Preparation of middle thirdPreparation of middle third

Preparation of the apical thirdPreparation of the apical third

Prepare to actual working lengthPrepare to actual working length Use 0.04 taper NiTi hand files in Use 0.04 taper NiTi hand files in

sequence smaller to largersequence smaller to larger

Preparation of apical thirdPreparation of apical third

Irrigation needle should have side opening to opening to preven driping of irrigant fluid hence pain

Acoustic streaming around a file in free water (left) and a schematic drawing (right).

cases

Extensive Amalgams-Extensive Amalgams-cancan be very be very painful necessitating endo-therapypainful necessitating endo-therapy