COMMON ERRORS

1. intact roof of pulp chamber

2. intact dentin shelf

3. perforation at the furcation

4. crown perforation

COMMON ERRORS IN ACCESS PREPARATION

FAILURE TO DEROOF PULP CHAMBER

most common error of students in access preparation

middle third of the crown

where the roof of pulp chamber, which is the start of pulp chamber is located

1. law of color change

2. ledge

3. location

how will you identify if the roof is still intact?

1. failure to drop at the center

2. incomplete deroofing

3. failure to assess anatomy

4. preshaping the outline

main reason for the failure in retaining the roof of pulp chamber

CERVICAL BULGE

most of accessory canals in molars are hidden in?

FUSION LINE

gives the idea that there is an accessory canal

1. failure to assess the OD radiographs

2. failure to limit deroofing up to the walls of the canal

CAUSES OF PERFORATION AT THE FURCATION

1. failure to assess radiograph

2. failure to drill at the center of the crown

CAUSES OF CROWN PERFORATION

PERPENDICULAR TO THE OCCLUSAL TABLE

angulation of drill on a multirooted teeth or premolar

1. divide the crown into three

2. 45 degree angle at the center

3. redirect bur at the middle of the root

PROCESS USED IN CALCIFIED TOOTH

1. orientation of the direction of the drilling

2. orientation of the root

3. evaluation of radiographs before

KEYS IN A CALCIFIED TOOTH

1. under instrumentation

2. ledge formation

3. apical perforation

COMMON ERRORS IN CANAL SHAPING

UNDER INSTRUMENTATION

error in canal shaping where the working length of the root canal was not negotiation leaving an undebrided apical portion

1. error in working length registration

2. failure in negotiating curved canals

3. canal blockage

CAUSES OF UNDER INSTRUMENTATION

1. undebrided and infected canal

2. ledge formation

3. persisted periapical lesion and symptoms

EFFECTS OF UNDER INSTRUMENTATION

LEDGE FORMATION

an artificially created irregularity on the surface of the root canal wall that prevents the placement of instrument to the apex of a patent canal

1. insertion of uncurved file HAFI short of the working length with excessive amount of apical pressure

2. repeated insertion of PARI with pressure in canals with abrupt curvature apically

3. allowing PARI to rotate in a position longer than necessary in a curved canal

CAUSES OF LEDGE FORMATION

1. early recognition

2. surgical intervention

3. schedule periodic calls

MANAGEMENT OF LEDGE FORMATION

APICAL PERFORATION

a torn and enlarged apical foramen due to the insertion of shaping instruments beyond the apical foramen

overzealous filing out of dentin in the inner curvature of the file

LATERAL PERFORATION

1. over estimation of working length

2. failure to constantly verify working length on instrument

3. loose instrument rubber stop

CAUSES OF APICAL PERFORATION

1. apical foramen

2. DCJ

3. apical constriction

IMPORTANT ANATOMY OF THE APICAL THIRD

1. loss of apical constriction

2. enlarged apical foramen

3. mechanical and chemical irritation of the periapex

4. periapical pathosis

5. seeping canal

6. no control in overfilling

EFFECTS OF APICAL PERFORATION

ENLARGED APICAL FORAMEN

• tear drop shaped

• traumatized bone & periapical involvement

• lose apical matrix

• seepage/weeping canal