Endodontic Re-treatment

Question 1

What are the management options for a RCFed tooth with a periapical radiolucency?

Answer 1

Endo retreatment

Periapical surgery

Extraction +/- prosthesis

Leave and review

Question 2

What causes periapical radiolucencies?

Answer 2

Numerous different conditions all of which require different clinical management:

Apical periodontitis (secondary)

Chronic apical periodontitis

Infection:

Secondary acute apical abscess, chronic apical abscess, and extra-radicular infection

Periapical cyst: Pocket cyst or true cyst

Periapical scar

Other pathosis: Non-endodontic origin

Foreign body reaction

Question 3

Which periapical conditions are treated by endodontic retreatment?

Answer 3

Secondary acute apical periodontitis

Chronic apical periodontitis

Secondary acute apical abscess and chronic apical abscess

Periapical cyst (Pocket cyst)

Question 4

Which conditions are treated by periapical surgery?

Answer 4

Apical periodontitis (Foreign body reaction)

Infection (Extra-radicular infection)

Periapical cyst (true cyst)

Question 5

How is a periapical scar treated?

Answer 5

Review and reassess

Question 6

Can treatment of the cause of the periapical radiolucency lead to damage in periapical tissues?

Answer 6

If treated, periapical tissues can heal.

Question 7

How does endodontic retreatment take place?

Answer 7

Remove all restorations from the tooth as well as cause of the problem.

Locate canals and remove existing RCF

Place initial dressing (Ledermix +/- Ca(OH)2 mixture)

Perform a comprehensive interim restoration

Question 8

How does endodontic retreatment take place?

Answer 8

1st appointment:

Remove all restorations from the tooth as well as cause of the problem.

Locate canals and remove existing RCF

Place initial dressing (Ledermix +/- Ca(OH)2 mixture)

Perform a comprehensive interim restoration

2nd appointment:

Access through interim restoration

Establish working lengths

Prepare, clean and disinfect canals

Place 2nd dressing (Ca(OH)2 paste or Led/Ca(OH)2 mixture)

Temporary filling in access cavity (CW, Cavit, IRM)

3rd appointment:

Varies - depends on diagnosis and treatment plan: Either change of dressing or RCF

Temporary filling in access cavity

Question 9

How is a crown removed?

Answer 9

Using specific tools called crown removers (eg auto abdicator crown remover or the aesculap crown remover)

First the crown is sectioned with a high speed beaver bur and then removed with a crown remover

Question 10

What devices can be used to remove a crown?

Answer 10

Autoabdicator

Aesculap remover

Question 11

What devices can be used to remove a post?

Answer 11

Eggler post remover

Masserann kit (usually used in conjunction with ultrasonic vibration)

Ultrasonic tips for post removal (Used on each side of the post to remove it slowly)

Howe’s pliers can be used to remove screw-type posts

NEVER DRILL OUT A POST

Question 12

How effective are typical post removal procedures?

Answer 12

An experiment by Abbott 2001 showed 100% success rate with removal

Question 13

How is gutta perca removed?

Answer 13

Heated instruments

Gates-Glidden burs

Solvents (Eucalyptus oil, chlorophorm, orange oil)

Hedstrom files (Insert file until resistance, 1/8th turn to engage GP, pull stroke to remove GP, repeat + Circumferential filing action)

Question 14

What factors are associated with unfavourable cases?

Answer 14

Vertical root fractures

Canal not found - calcified

Perforation repair unfavourable + had previous surgery

Patient refused surgery + had previous surgery + retrograde amalgam RCF

Question 15

What factors are associated with uncertain cases?

Answer 15

More time required (area smaller)

RCF not redone prior to surgery

Possible vertical root fracture

Patient refused surgery

Previous surgery

Question 16

What outcome is the most common outcome following endodontic re-treatment? Why?

Answer 16

Favourable outcome higher than most other studies. This is because treatment protocol:

Removed all potential causative factors

Comprehensive interim restorations were used

Combination of irrigants - EDTAC + NaOCl used

Medicament regime to suit the diagnosis

Longer periods of intra canal dressings

Reassessment of healing response prior to RCF

Question 17

What indictions are specific to lead to surgery?

Answer 17

Specific indications for surgery include: True cysts, extra-radicular infection, and FBr

Question 18

Should endodontic re-treatment still be preferably done if the tooth has a crown and a post?

Answer 18

Crowns and posts can be predictably removed from teeth to allow endodontic re-treatment. It shouldn’t be a reason by itself to indicate surgery should be done rather than orthograde re-treatment.