7. Endodontic Failure

Question 1

What is the success rate for teeth with periapical lesions?

Answer 1

86%

Question 2

What is the success rate for retreated teeth?

Answer 2

62%

Question 3

How would you check that a tooth has been endodontically treated successfully?

Answer 3

No symptoms
Retention of tooth
Function
Radiographic evidence of healing

Question 4

What signs of endodontic failure might you see in a radiograph post-treatment?

Answer 4

Under extended fillings
Over extended fillings
Poorly compacted fillings
Poor coronal seal

Question 5

What reasons for failure may occur before treatment?

Answer 5

Misdiagnosis

Poor case selection

Question 6

What reasons for failure may occur during treatment?

Answer 6

Missed canals
Ineffective clean, shape or fill
Iatrogenic damage

Question 7

What reasons for failure may occur after treatment?

Answer 7

Recurrent caries
Coronal leakage
Post hole preparation problems

Question 8

What is the success rate for teeth without periapical lesions?

Answer 8

96%

Question 9

How can you manage endodontic failure?

Answer 9

Monitor
Fix it yourself
Attempt orthograde retreatment 
Peri-radicular surgery
Refer to a specialist e.g. Perforation, separated instrument
Extraction e.g. Crown/root fracture

Question 10

In retreatment cases, how would you remove insoluble resins?

Answer 10

Ultrasonic scalers

Question 11

In retreatment cases, how would you remove gutta percha?

Answer 11

Hand files +/- solvents

Protaper

Question 12

In retreatment cases, how would you remove soluble pastes?

Answer 12

Hand files +/- solvents

Protaper