cleaning and shaping

1. BIO-MECHANICAL PREPARATION
THE ROAD MAP TO SUCCESS…
v.chandrasekhar
prof&hod

2. INTRODUCTION

3.  The successful endodontic therapy
depends on cutting a correct access
opening followed by thorough
biomechanical cleaning and a three
dimensional obturation…
 Although each of these steps is a separate
procedure, errors in performing anyone of
them can decrease the overall success of
endodontic therapy.

4.  The preparation of the root canal space involves
three separate procedures:
These procedures are challenging and constitute a major portion of the effort in
root canal treatment. In addition to the removal of the irritants, the preparation
of the canal is important to ensure adequate canal obturation.
CLEANING SHAPING
APICAL PREPARATION

5.  The cleaning refers to the removal of all
contents of the root canal system before and
during shaping.
 Organic substances, micro flora, bacterial by-
products, food, caries, denticles, pulp stones,
dense collagen, previous root canal filling
material and dentinal fillings resulting from root
canal preparation.
CLEANING / DEBRIDEMENT

6.  Shaping refers to a specific cavity form with specific
objectives.
 The shape permits vertical pluggers to fit freely within
the root canal system and to generate the hydraulics
required to transform and capture a maximum cushion
of the Gutta Percha and a micro film of sealer into all
foramina.
SHAPING

7. APICAL PREPARATION
 It is critical to prepare an apical matrix or barrier at
proper working length..
 This barrier has two functions:
- To serve as a stop against which to condense gutta-
percha.
-To prevent materials,irrigants,and instruments from
extruding into the periapical tissues, with resultant
irritation & inflammation.

8. DEFINITION
BIO MECHANICAL PREPARATION
It is the attainment of free access to the apical foramen, through the root canal,
by mechanical means without injuring the periapical tissue.

9. OBJECTIVES OF ROOT CANAL PREPARATION
 Do no harm
 Totally clean the root canal system
 Create a continuously tapering root canal
preparation
 Keep the apical constricture small and in its
original position
 Assume curvature in all canals
 Avoid aggressive apical instrumentation
 Accurately pre bend the instruments
 Avoid apical blockage
 Avoid over zealous canal shaping

10. RULES FOR ROOT CANAL CLEANING AND SHAPING
 Direct access should be obtained along the straight
lines
 The length of the tooth should be accurately
determined
 Instruments should be used in a sequence of sizes
with periodic recapitulation and without skipping
of the sizes
 Instruments should be used with a quarter to half
turn and withdrawn with a full stroke
 The barbed broaches should be used cautiously and
only when the root canal is wide enough to permit
their insertion and rotation without binding
 Instruments should be fitted with stoppers

11.  The apical portion of the root canal, 3 – 4 mm
should be enlarged at least 3 sizes greater than
the first instrument that binds until the walls are
tapered, without irregularities.
 One must not force an instrument if it binds.
 Instruments should be checked for deformation
and discarded if strain is present.
 All instrumentation should be done using sterile
instruments in a wet canal.
 Debris should not be forced through the apical
foramina.
 Instruments should be confined to the root
canal, to prevent trauma to periapical tissue.

12. PRECAUTIONS DURING INSTRUMENTATION
 A root canal instrument should not be forced if it
binds
 To force an instrument, it is to invite to breakage of an
instrument
 Always only controlled finger pressure should be used
in manipulating an instrument in the root canal.
 Always instrumentation of root canal should be done
in a wet canal.
 Instruments must be used extra vagantly particularly in
the smaller sizes
 Once the working length of a tooth is determined, all
instruments must be kept within the confines of the
root canal.

13. INSTRUMENTATION TECHNIQUES
HAND INSTRUMENTATION ROTARY INSTRUMENTATION
• STEP-BACK (TELESCOPIC)
• STEP – DOWN
• CROWN DOWN PRESSURE LESS
TECHNIQUE
• BALANCED FORCE TECHNIQUE
• DOUBLE FLARED TECHNIQUE
• REVERSE FLARED TECHNIQUE
• ENDOSONICS
• QUANTEC SERIES
• GREATER TAPER SERIES
• PROFILE SERIES
• PROTAPER SERIES
• LIGHT SPEED
INSTRUMENTATION

14. STEP BACK TECHNIQUE / TELESCOPIC TECHNIQUE
FIRST DESCRIBED BY MARTIN

15. STEP BACK TECHNIQUE

16. ADVANTAGES
 It is less likely to cause periapical trauma
 It facilitates the removal of more debris
 The greater place that results from
instrumentation facilitates packing of additional
gutta percha cones by either the lateral or
vertical condensation method
 The development of apical matrix or stops,
prevents over filling of the root canal.

17. DISADVANTAGES
 The pulpal debris and bacteria may be pushed apically and even
extruded into the periapical tissues, causing blockages and post-
operative discomfort..
 Irrigation, critical part of debridement stage, cannot penetrate
to the apex because of narrowness of the canals.
 Establishing the working length, especially in calcified canals is
difficult as interferences could prevent apical movement of the
file.

18. STEP-DOWN TECHNIQUE
FIRST INTRODUCED BY GEORGE et al in 1982

19. ADVANTAGES
• REMOVAL OF CORONAL INTERFERENCE
• STRAIGHTER ACCESS TO THE APICAL THIRD OF
THE ROOT
• REMOVAL OF CANAL CONTENTS AND
MICROORGANISMS BEFORE APICAL PREPARTION
• INCREASED SPACE FOR INSTRUMENTATION AND
IRRIGATION OF THE APICAL THIRD OF THE ROOT
• MINIMAL APICAL EXTRUSION OF THE DEBRIS

20. DISADVANTAGES
 Coronal portion can be over prepared and
under irrigated.
 Could results in ledges and blockages, and
with over zealous use of the files a
perforation or strip may be created on the
inner wall of the curved canals.
 In calcified teeth, working length has to be
obtained first.

21. CROWN-DOWN PRESSURELESS TECHNIQUE

22. ADVANTAGES
 REMOVAL OF CORONAL INTERFERENCE
 STRAIGHTER ACCESS TO THE APICAL THIRD OF
THE ROOT
 REMOVAL OF CANAL CONTENTS AND MICRO-
ORGANISMS BEFORE APICAL PREPARATION
 INCREASED SPACE FOR INSTRUMENTATION AND
IRRIGATION OF THE APICAL THIRD OF THE ROOT
 MINIMAL APICAL EXTRUSION OF THE DEBRIS

23. DISADVANTAGES
 Coronal portion can be over
prepared and under irrigated.
 Could results in ledges and
blockages, and with over zealous
use of the files a perforation or strip
may be created on the inner curve
 In calcified teeth, working length has
to be obtained first.

24. BALANCED FORCE TECHNIQUE..
FIRST INTRODUCED BY ROANE et al in 1985
PHASE I
PHASE III
PHASE II

25. ADVANTAGES
EFFECTIVE REMOVAL OF DEBRIS
 EFFECTIVE IN REDUCING CANAL
TRANSPORTATION, INSTRUMENT
BREAKAGE AND STRIPPING
PERFORATIONS
 MINIMAL APICAL EXTRUSION OF THE
DEBRIS

26. DOUBLE FLARED TECHNIQUE
Introduced by Favo (1983) similar to crown down pressure less
technique.
Phase I : A cervical – apical flaring was performed using
Gates Glidden and larger files followed by smaller files.
Phase II: characterized by development of apical matrix.
After reaching the correct working length, 2 or 3
instruments are used in sequential order
Phase III: Is performed in an apical – cervical direction to
achieve enhancement of canal and cleanliness. It is similar
to standard step back technique.

27. REVERSE FLARING TECHNIQUE
 DEVELOPED BY WEINE IN 1989.
 ALSO KNOWN AS PRE-FLARING.
 IT MAY BE ACHIEVED BY USING GATES GLIDDEN
DRILLS OR BY HAND INSTRUMENTS
 ASPECTS INVOLVED IN THIS TECHNIQUE :
 MINIMAL FILING DONE AT THE APICAL THIRD
 ENLARGEMENT OF THE CORONAL PORTION
FOLLOWED BY APICAL FLARING

28. ADVANTAGES
 IRRIGANTS ARE ALLOWED TO GET DOWN THE
CANAL EARLIER TO PRODUCE BETTER
CLEANING
 USEFUL IN EXTREMELY CURVED CANALS
 STRAIGHTER ACCESS TO THE APICAL REGION
 ELIMINATION OF INTERFERENCE IN THE
CORONAL TWO-THIRDS OF THE ROOT

29. PROFILE SERIES

30. P
R
O
T
A
P
E
R
S
E
R
I
E
S

33. ENDODONTICMISHAPS OR PROCEDURAL
ACCIDENTSARE THOSEUNFORTUNATE
OCCURENCESTHAT HAPPENDURING
TREATMENT, SOMEOWINGTO
INATTENTION TO DETAIL, OTHERS
TOTAL UNPREDICTABLE!!!

34. • LOSS OF WORKING LENGTH
• BLOCKAGE OF THE CANAL SYSTEM
• LEDGING
• BREAKAGE OF INSTRUMENTS IN THE CANAL
• ZIPPING (ELLIPTICATION)
• STRIPPING OR LATERAL WALL PERFORATION
• OVERINSTRUMENTATION
• OVERPREPARATION/UNDERPREPARATION

35. CAUSES:
-Due to rapid in creases in file
size and accumulation of
dentinal debris in the apical one
third of the canal
- Malpositioned instrument stops
PREVENTIVE MEASURES:
-Frequent irrigation with NaOCl
-Recapitulation
-Periodic radiographic verification
of working length
-Proper use of instruments stops
-Use of directional stops in
curved canals

36. BLOCKAGE IS AN OBSTRUCTION
IN A PREVIOUSLY PATENT CANAL
SYSTEM THAT PREVENTS ACCESS
TO THE APICAL CONSTRICTION OR
APICAL STOP.
CAUSES:
-PACKING OF DENTIN CHIPS, TISSUE
DEBRIS, RESTORATIVE MATERIALS,
COTTON PELLETS,PAPER POINTS OR
A FRACTURED INSTRUMENT IN THE
CANAL

37. A LEDGE IS AN ARTIFICIALLY CREATED
IRREGULARITY ON THE SURFACE OF THE
ROOT CANAL WALL THAT PREVENTS THE
PLACEMENT OF INSTRUMENTS TO THE
APEX OF AN OTHERWISE PATENT CANAL
CAUSES
INSERTION OF UNCURVED INSTRUMENTS
SHORT OF WORKING LENGTH WITH
EXCESSIVE AMOUNTS OF APICAL
PRESSURE.
PREVENTION
-BY PRE-CURVING OR OVER CURVING THE
APICAL 3-4 mm OF THE FILE WITH THE SAME
CURVATURE AS THE CANAL DEPICTED IN
THE RADIOGRAPH
-BY-PASSING THE LEDGES IF SMALL
ENOUGH

38. CAUSED WHEN THE INSTRUMENT IS
INCORRECTLY USED. HAND
INSTRUMENTS,INCLUDING K-TYPE
FILES, HEDSTROM FILES ROTARY
INSTRUMENTS SUCH AS PEESO
REAMERS,GATES GLIDDEN BURS, AND
LENTULOS, AND CONDENSERS
ARE COMMONLY MISUSED DURING
ROOT CANAL TREATMENT

39. UNRAVELING OF FILE FLUTES PRIOR
TO INSTRUMENT FRACTURE… INSTRUMENTS THAT ARE BENT,TWISTED,
OR KINKED MUST BE DISCARDED….
PREVENTION OF SEPARATION OF INSTRUMENTS
IT REQUIRES KNOWLEDGE OF THE PHYSICAL CHARACTERISTICS OF THE
INSTRUMENTS AND THE GUIDELINES FOR THEIR PROPER USE IN THE
CANAL SYSTEM.GENERALLY THE INSTRUMENTS SHOULD BE DISCARDED
AND REPLACED WITH NEW INSTRUMENTS WHEN:
1) FLAWS, SUCH AS SHINY AREAS OR UNWINDING ARE DETECTED ON
THE FLUTES
2) INSTRUMENT BENDING OR CRIMPING OCCURS DUE TO EXCESSIVEUSE
3) THE FILE KINKS INSTEAD OF CURVING
4) CORROSION IS NOTED ON THE INSTRUMENT

40. REFERS TO TRANSPOSITION OR
TRANSPORTATION OF THE APICAL
PORTION OF THE CANAL…IT IS
CHARACTERIZED BY A NORMALLY
CURVED CANAL WHICH HAS BEEN
STRAIGHTENED, ESPECIALLY IN THE
APICAL THIRD
CAUSES
FAILURE TO PRECURVE FILES
ROTATION OF INSTRUMENTS IN CURVED
CANALS, AND THE USE OF LARGE , STIFF
INSTRUMENTS TO BORE OUT A CURVED
CANAL.
APICAL FORAMEN TENDS TO BECOME
TEARDROP SHAPED OR ELLIPTICAL

41. • FILES SHOULD BE OVER-CURVED , ESPECIALLY IN THE APICAL
3 TO 4 mm AND ALWAYS WORKED IN THE DIRECTION OF
CURVATURE WITH SHORT,IN-OUT STROKES ; DO NOT ROTATE
THE FILE OR CHANGE ITS ORIENTATION
• ANTI-CURVATURE OR REVERSE FILING SHOULD BE USED IN
CURVED CANALS AND IN ROOTS WITH DEEP PROXIMAL
INVAGINATIONS…

42. REFERS TO THINNING OF THE LATERAL
ROOT WALL WITH EVENTUAL
PERFORATION.
CAUSES
OVERZEALOUS INSTRUMENTATION
IN THE MID-ROOT AREAS OF
CERTAIN TEETH, USUALLY MOLARS
PREVENTION
USE OF ANTI-CURVATURE FILING.
CLEAN & SHAPE THE CANALS
USING SMALL FILES
EXTRAVAGANTLY & IN A
SEQUENTIAL MANNER.
AVOID USING LARGE-DIAMETER
INSTRUMENTS AS WELL AS ROTARY
INSTRUMENTS..

43. REPAIR OF PERFORATIONS USING A PHARMACEUTICAL
GRADE-CALCIUM HYDROXIDE MIXED WITH PHYSIOLOGIC SALINE OR LOCAL
ANESHETIC SOLUTION AND IS CARRIED TO THE CANAL SYSTEM VIA THE
LENTULO OR MCSPADDEN COMPACTOR AND VERTICALLY COMPACTED
AGAINST THE STRIP..
THE KEY FACTORS FOR REPAIR ARE IMMEDIATE SEALING OF THE
PERFORATION, WHICH PROTECTS IT FROM SALIVA AND OTHER
CONTAMINANTS AND PREVENTING PLACEMENT
OF SEALING MATERIALS INTO THE PERIDONTIUM

44. EXCESSIVE INSTRUMENTATION BEYOND THE
APICAL CONSRICTION VIOLATES THE
PERIODONTAL LIGAMENT AND ALVEOLAR
BONE…
LOSS OF APICAL CONSTRICTION CREATES:
AN OPEN APEX WITH INCREASED LIKELIHOOD
OF OVERFILLING
 LACK OF AN ADEQUATE APICAL SEAL
 PAIN & DISCOMFORT TO THE PATIENT

45. 1. Using good radiographic technique
2. Accurately determining the apical constriction of the root canal
3. Using sound reference points
4. Using stable instrument stops placed perpendicular to the shaft
of the instrument
5. Retaining all instruments within the confines of the canal
system.
6. Occlusal refinement or reduction prior to working length
determination and instrumentation
7. Periodic radiographic verification of the working length
8. Attention to detail during all cleaning and shaping procedures
and
9. Assessing the integrity of the apical stop with stiff paper points
or files.

47. IT IS THE EXCESSIVE REMOVAL OF TOOTH STRUCTURE IN A
MESIO-DISTAL
AND BUCCO-LINGUAL DIRECTION…
IT OCCURS IN THE APICAL, MIDDLE & CORONAL PORTIONS OF THE
CANAL
SYSTEM…
EXCESSIVE CANAL FLARING INCREASES THE CHANCES OF
STRIPPINGANDPERFORATION

48. IT IS THE FAILURE TO REMOVE PULP TISSUE, DENTINAL DEBRIS,
AND MICRO-ORGANISMS FROM THE ROOT CANAL SYSTEM…
IN ADDITION THE CANAL IS IMPROPERLY SHAPED, THUS
PREVENTINGTHREE-DIMENSIONAL OBTURATION…
UNDERPREPARED CANALS ARE BEST MANAGED BY ADHERING
TO SOUND PRINCIPLES OF :
- PROPER LENGTH DETERMINATION
- CANAL CLEANING & SHAPING
- RECAPITULATION
TREATMENT FOR OVERPREPARATION/UNDERPREPARATION IS
“RETREATMENT”

49. AS STATED BY MOLVEN AND HALVE :
SUCCESS DEPENDS ON THE ELIMINATION OF
PROCEDURAL ACCIDENTS WHEN TREATMENT
STARTS AS WELL AS DURING THE TREATMENT;
AND THE PREVENTION OF THESE MISHAPS
DURING THE TREATMENT.
“SUCCESS IN ENDODONTICS REFLECTS THE
STANDARD OF CLEANING, SHAPING AND
FILLING OF ROOT CANALS”