This document discusses the cleaning and shaping of root canals. It defines cleaning as the removal of pathogenic contents from the root canal and shaping as creating a 3D tapered shape that is widest coronally and narrowest apically. The objectives of shaping are outlined as both mechanical and biological to remove debris without forcing it periapically and create sufficient space for obturation. Various techniques are described such as step-back, crown-down, and hybrid techniques. Considerations like instrument movements, irrigation methods, and the goals of apical enlargement are also covered.

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:
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

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
I. NEGOTIATION (PATENCY FILING)
II. CORONAL PRE-ENLARGEMENT
III. WORKING LENGTH DETERMINATION
IV. SHAPING TECHNIQUES
V. 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

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

14. 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

16. 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

18. Step back crown down hybrid

19. HYBRID TECHNIQUE

20. Advancements

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

22. 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 force movements
Chlorhexidine irrigation
EDTA for removal of smear
layer
Apical enlargement- as small
as possible
Depends upon-
o periapical pathology
o pulp-vital/infected/calcified
TRADITIONAL CONCEPT CURRENT CONCEPT