Periradicular Surgery

Question 1

Aims of PR surgery
(2)

Answer 1

1. Achieve apical seal
2. Remove existing infection

Question 2

Possible causes of Endo failure
(12)

Answer 2

-calcification
-broken instrument
-root dilaceration
-root #
-underfilled
-overfilled
-open apex
-lateral canals
-lateral perforation
-poor host tissue response
-apical cyst/other inf
-poor coronal seal/pros failure

Question 3

Suggesrt some flap designs for PRS
(4)

Answer 3

-semilunar
-2 sided
-3 sided
-Ochsenbein-Luebke flap

Question 4

Describe the steps for PRS

Answer 4

-LA
-cut flap
-retract tissue
-bone removal - electric hp
-apex removal 3mm
-enucleation of granulation tissue
-seal
replace flap and suture
-seal

Question 5

Suggested retrograde sealers

Answer 5

-amalgam (seldom)
-MTA
-resin modified ZOE

Question 6

Suggested method of removal of old root filling

Answer 6

Ultrasonic

Question 7

Properties of RM ZOE
-positive
-negative

Answer 7

-Cheap
-Easy to use
-Radiopaque
-Bacteriostatic

-Sensitive to moisture
-May resorb
-Doesn’t promote cementogenesis

Question 8

Properties of MTA
-positive
-negative

Answer 8

-Moisture resistant’
-Promotes cementogenesis
-Very good seal

-Expensive
-Long setting time
-Difficult to use
-can cause dryinging/reduction in moisture in canal = tooth more brittle/prone to #