Biomechanical preparation in endodontics

cleaning and shaping of root canals in endodontic treatment procedure

1. KARISHMA ASHOK IV/II ROLL NO 31 CLEANING & SHAPING OF ROOT CANALS…..

2. 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

3. MECHANICAL OBJECTIVES: CONTINUOUS TAPERING CONICAL SHAPE NARROW APICALLY AND WIDEST CORONALLY CONCEPT OF FLOW (MULTIPLE PLANES) APICAL FORAMEN AS NARROW AS POSSIBLE AVOID TRANSPOTATION OF APICAL FORAMEN

4. 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

5. CLINICAL OBJECTIVES Removal of overlying dentin straight line access Hermetic seal in obturation Permanent restoration form function & aesthetics

6. ANATOMICAL CONSIDERATION

7. PRINCIPLES OF CANAL INSTRUMENTATION STRAIGHT LINE ACCESS PRECURVING RETAINING ITS ORIGINAL FORM & SHAPE IRRIGATION RESTRICTING INSTRUMENTS WITHIN THE CANAL RECAPITULATION REMOVAL OF DENTINAL DEBRIS

8. PHASES IN SHAPING OF ROOT CANAL NEGOTIATION (PATENCY FILING) CORONAL PRE-ENLARGEMENT WORKING LENGTH DETERMINATION SHAPING TECHNIQUES WORKING WIDTH

9. PATENCY FILING PRECURVED ISO SIZE 10 FILE / STAINLESS K FILE REAMING MOTION IN 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

10. CORONAL PRE-ENLARGEMENT ADVANTAGES : REDUCED POTENTIAL OF EXCRUCIATING DEBRIS BEYOND APEX APICAL GAUGING MORE ACCURATE PREVENTS PREMATURE BINDING OF INSTRUMENTS TO CANAL WALLS BETTER IRRIGATION 3-4 MM INTO CANAL SPACE ORIFICE ENLARGERS (NI-TI SYSTEM/ GG DRILLS)

11. MOVEMENTS IN BMP FILING WATCH WINDING

12. TECHNIQUES STEP BACK TECHNIQUE CROWN DOWN TECHNIQUE CONVENTIONAL PRESSURELESS PASSIVE DOUBLE FLARE BALANCED FORCE HYBRID TECHNIQUE

13. STEP BACK TECHNIQUE No 10 & No 15 FILE INSERTED TILL WORKING LENGTH; USE IN REAMING MOTION APICAL ENLARGEMENT TO DEVELOP APICAL STOP ATLEAST 3 SIZES (25 FILE SIZE) INCREAZE FILE SIZE PROGRESSIVELY & WORKING SHORT BY 1 MM RECAPITULATION AFTER PREPARING THE BODY OF CANAL, NOS 2 & 3 GATES GLIDEN DRILLS ARE USED FOR CORONAL PREPARATION CIRCUMFERENTIAL FILING USING MAF

14. 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 MAF FINAL TAPER WITH CIRCUMFERRENTIAL FILING

15. Step back crown down hybrid

16. HYBRID TECHNIQUE

17. Advancements

18. ULTRASONIC INSTRUMENTS Richman Cavitation & acoustic streaming File movement 20,000-25,000 vibrations/second Sodium hypochlorite – irrigation Disadvg : over instrumentation transportation of foramen

19. Cleaning & shaping Step back technique Filing & reaming motion Sodium hypochlorite irrigation Apical enlargement- 3 sizes beyond the first instrument size used Enlarge canal until healthy dentine appears Shaping & cleaning Crown down tecnique Balanced f orce movements Chlorhexidine irrigation EDTA for removal of smear layer Apical enlargement- as small as possible Depends upon- periapical pathology pulp-vital/infected/calcified TRADITIONAL CONCEPT CURRENT CONCEPT