KARISHMA ASHOKIV/IIROLL NO 31

CLEANING & SHAPINGOF ROOT

CANALS…..

INTRODUCTION:DEFINITIONS Cleaning: removal of all potentially pathogenic

contents from root canal Shaping: dual action – 3D prgogressive access- apical prep to permit final obturation instruments &

materials to fit easily

OBJECTIVES

MECHANICAL OBJECTIVES:1. CONTINUOUS

TAPERING CONICAL SHAPE

2. NARROW APICALLY AND WIDEST CORONALLY

3. CONCEPT OF FLOW (MULTIPLE PLANES)

4. APICAL FORAMEN AS NARROW AS POSSIBLE

5. AVOID TRANSPOTATION OF APICAL FORAMEN

BIOLOGICAL OBJECTIVES: CONFINEMENT OF INSTRUMENT TO THE ROOTS

NECROTIC DEBRIS NOT FORCED PERIAPICALLY

COMPLETE REMOVAL OF TISSUE FROM THE CANAL SPACE

CREATION OF SUFFICIENT SPACE FOR OBTURATING MATERIAL

CLINICAL OBJECTIVESRemoval of overlying dentin straight line access

Hermetic seal in obturationPermanent restoration form function & aesthetics

ANATOMICAL CONSIDERATION

PRINCIPLES OF CANAL INSTRUMENTATION STRAIGHT LINE ACCESSPRECURVINGRETAINING ITS ORIGINAL FORM & SHAPEIRRIGATIONRESTRICTING INSTRUMENTS WITHIN THE CANALRECAPITULATIONREMOVAL OF DENTINAL DEBRIS

PHASES IN SHAPING OF ROOT CANAL

I. NEGOTIATION (PATENCY FILING)

II. CORONAL PRE-ENLARGEMENT

III. WORKING LENGTH DETERMINATION

IV. SHAPING TECHNIQUES

V. WORKING WIDTH

PATENCY FILING PRECURVED ISO SIZE 10 FILE / STAINLESS K FILE

REAMING MOTIONIN CALCIFIED CANALS OR WITH OBSTRUCTIONS, ISO SIZE 8 FILE OR SIZE 6 K FILE

CREATING A PATH PASSIVELY TO THE APICAL FORAMEN

HELPS IN MAINTAINING A CONTINUOUS & CLEAR PATH BY REMOVING DEBRIS ESP. WHEN COMBINED WITH IRRIGATION

CORONAL PRE-ENLARGEMENT ADVANTAGES: REDUCED POTENTIAL OF EXCRUCIATING DEBRIS BEYOND APEX

APICAL GAUGING MORE ACCURATEPREVENTS PREMATURE BINDING OF INSTRUMENTS TO CANAL WALLS

BETTER IRRIGATION

3-4 MM INTO CANAL SPACEORIFICE ENLARGERS (NI-TI SYSTEM/ GG DRILLS)

MOVEMENTS IN BMPFILING

WATCH WINDING

TECHNIQUES

STEP BACK TECHNIQUE CROWN DOWN TECHNIQUE CONVENTIONAL PRESSURELESSPASSIVE DOUBLE FLARE

BALANCED FORCEHYBRID TECHNIQUE

STEP BACK TECHNIQUENo 10 & No 15 FILE INSERTED TILL WORKING

LENGTH; USE IN REAMING MOTIONAPICAL ENLARGEMENT TO DEVELOP APICAL

STOP ATLEAST 3 SIZES (25 FILE SIZE) INCREAZE FILE SIZE PROGRESSIVELY &

WORKING SHORT BY 1 MM RECAPITULATIONAFTER PREPARING THE BODY OF CANAL, NOS 2

& 3 GATES GLIDEN DRILLS ARE USED FOR CORONAL PREPARATION

CIRCUMFERENTIAL FILING USING MAF

CROWN DOWN TECHNIQUE CORONAL FLARING WITH GG DRILLS NO 2 OR 3 WITH EACH FILE BEING SEQUENTIALLY SHORTER

A LARGE FILE (SIZE 60) IS PLACED IN CORONAL ASPECT & CANAL IS INSTRUMENTED IN WATCH WINDING MOTION

SEQUENTIALLY SMALLER FILES TILL WORKING LENGTH

APICAL ENLARGEMENT WITH MAFFINAL TAPER WITH CIRCUMFERRENTIAL FILING

Step back crown down hybrid

HYBRID TECHNIQUE

Advancements

ULTRASONIC INSTRUMENTSRichmanCavitation & acoustic streamingFile movement 20,000-25,000 vibrations/secondSodium hypochlorite – irrigationDisadvg: over instrumentation

transportation of foramen

Cleaning & shapingStep back techniqueFiling & reaming motionSodium hypochlorite irrigation

Apical enlargement- 3 sizes beyond the first instrument size used

Enlarge canal until healthy dentine appears

Shaping & cleaningCrown down tecniqueBalanced force movements

Chlorhexidine irrigationEDTA for removal of smear layer

Apical enlargement- as small as possible

Depends upon-o periapical pathologyo pulp-vital/infected/

calcified

TRADITIONAL CONCEPT CURRENT CONCEPT