P3-ENDO-CHAPTER 9 PPT

major objective of the root canal treatment procedure

Remove contents of the pulp space and shape the walls of the canal to receive the filling material

Refers to the removal of all contents of the root canal system before and during shaping

Cleaning

Refers to specific cavity form with five objectives

Shaping

Cleaning and shaping uses what type of preparation

Biomechanical or chemomechanical

5 shaping objectives are

Develop a continuously tapering conical form in the root canal preparation

Make the canal narrower apically, with the narrowest cross-sectional diameter at its terminus

Make the preparation in multiple planes

Never transport the foramen

Keep the apical foramen as small as its practical

5 phases of cleaning and shaping

Negotiating the canal- patency filing

Coronal enlargement

Working length measurement

Root canal shaping technique

Root canal working width

In coronal pre-enlargement use

Gg

K files

Sx files

Working length should be always short as

0.5-1mm

Ideal gauge for root canal

25-30

Biological objective is to completely debride the pulp from

Pulp tissue

Bacteria/microorganisms

Dentinal debris

Endotoxins

Weine's Rules for canal preparation are

Preparation must enlarge the canal while maintaining the general form of the preoperative shape, but it also must develop the most desirable shape to fill

Once working length is determined all instruments should be kept within the confines the canal.

Instruments must be used extravagantly, especially the smaller sizes.

Canals must be prepared in wet environment.

Motions of instrument manipulation is also known as

Envelopes of motion

Motions of instrument manipulation are

Filing

Reaming

Turn and Pull

Watch Winding

Balanced force instrumentation

Anti-curvature filing

Indicates a push-pull action with the instrument

Filing

Instrument is moved from buccal to medial to lingual to distal

Circumferential filing

Indicates clockwise or right-hand rotation of an instrument

Reaming

Reaming can cause

Enlargement of the canal and cuts the dentin

Clockwise rotation in reaming how many twisting

1/4 or 1/2 twisting

A quarter turn to the right is followed by a straight outward pull.

Turn and Pull action

Back and forth oscillation of a file 30-60 degrees right and 30-60 degrees left

Watch winding motion

Balanced force technique is by

James B. Roane 1985

Instrument is engaged with apical pressure 1/4 turn and then apical pressure 3/4 turn counterclockwise, hear a click means cuts dentin

Balance force technique

Balance force technique is repeat sequence for

2-3 times

Anti-curvature filing is put forward by

Abou-rass,Frank, and Glick

Involves filing away from the inner curve of a root to reduce the risk of a strip perforation

Anti-curvature filing

Re-instrumentation with a smaller instrument following each irrigation step.

Recapitulation

Use of a smaller instrument remove debris produced during instrumentation

Recapitulation

Recapitulation prevents

Pushing debris beyond the apex and apical plus formation

Techniques of pulp space preparation

Apical to coronal

Coronal to apical

Hybrid technique

Apical to coronal other term

Standardized preparation

Step back preparation

Roane balanced force

Telescopic, Serial Root canal prep

Modifications of step back technique

Schilder

Weine

Passive step back

Coronal to apical other term

Step down technique

Double flare technique

Crown down pressure less technique

Step back step down combination procedure

Hybrid technique

Advantage of step back technique

Conservation of tooth structure especially in cervical third

Disadvantages of step back

Apical plug

Decreased volume of irrigating solution

Procedural mishaps

Step back preparation phase I is

Apical preparation up to the file #25 MAF to full WL with recapitulation using prior size files

Step back phase II

Stepping back procedure in 1mm increments

Recapitulation with #25 file till full working length

Phase II-A is also known as

Refining phase

Phase II-A uses

Gates glidden no. 2,3,4 to create coronal and middle preparations

Phase II-B in step back is

Return to #25 last file

Files used to smooth the step back with vertical push-pull strokers

H files

Gutmann said that

Final prep should be exact replica of original canal configuration

Final preparation smooth taper advantages

Better tactile awareness

Keeps apical preparation small on its original position gradual layer

Ability to prepare proper apical stop

Avoid zipping

Final preparation smooth taper disadvantages

Chances of pushing debris into periradicular tissues

WL likely to change as canal curvatures are eliminated

Step down preparation is first suggested by

Schilder in 1974

Step down is named and described the technique in detail

Goerig in 1982

Principle of step down preparation

Coronal aspect of the root canal is prepared and cleaned before the apical part

Step down preparation is filled first with

Sodium hypochlorite

Step down preparation is explored first with

Fine, stainless steel, .02 taper

If step down preparation will not reach the apical constriction use

.04 or .06 taper or gates glidden drill

Step down preparation is used to prepare to the depth of

16-18mm or to the beginning of the curve using 15,20,25

In step down preparation these are used to refine coronal preparation

Gates glidden 1,2, and 3

Ideal termination size is

25 or 30

Would tell the size for obturation

MAF

Mishaps during cleaning and shaping

Loss of working length

Blockage of the canal system

Ledging

Breakage of instruments in the canal

Zipping

Stripping or lateral wall perforation

Overinstrumentation

Overpreparation or underpreparation

It is caused by rapid increase in file size and accumulation of dentinal debris in the apical one third of the canal

Loss of working length

It is caused by packing of dentin chips, tissue debris, restorative materials, cotton pellets, paper points, or a fractured instrument in the canal

Blockage of the canal system

Artificially created irregularity on the surface of the root canal wall

Ledging

Causes of breakage of instruments in the canal

Torsional fatigue

Flexural fatigue

Management of blockage of instruments in the canal

Bypass

Retrieval

Refers to transportation of the apical portion of the canal

Zipping

Characterized by a normally curved canal which has been straightened, especially in the apical third

Zipping

Refers to thinning of the lateral root wall with eventual perforation

Stripping or lateral wall perforation

Caused of stripping or lateral wall perforation

Overzealous instrumentation in the mid-root areas of certain teeth, usually molars

Violates the periodontal ligament and alveolar bone

Over-instrumentation

Loss of apical constriction creates

An open apex

Lack of adequate apical seal

Pain and discomfort to the patients

Failure to remove pulp tissue, dentinal debris, and microorganisms from the root canal system

Under-preparation

Underprepared canals are best managed by adhering to sound principles of

Proper length determination

Canal cleaning and shaping

Recapitulation

Treatment for underpreparation

Retreatment