13 - Endodontic interface

Question 1

What guidelines are used for endodontic diagnosis?

Answer 1

AAE

Question 2

What are reasons that RCT teeth continue to be symptomatic?

Answer 2

• PDL
• bone
• microorganisms
• tooth not sterile
• lateral or accessory canals

Question 3

What questions should you ask the patient when considering re-RCT?

Answer 3

• when was the initial RCT?
• why was it required?
• did treatment improve the symptoms? (wrong tooth?)
• have the symptoms changed?
• was dental dam used?
• how many RCT on this tooth?

Question 4

What is involved in an endodontic examination?

Answer 4

• EO
• IO
• STE
• swelling
• sinus tracts
• apical palpation
• percussion
• mobility
• periodontal exam

Question 5

What does a long thin pocket indicate?

Answer 5

Vertical fracture

Question 6

What special tests can be used?

Answer 6

• radiographs
• bite test
• test cavity
• staining/transillumination
• selective anaesthesia

Question 7

What is a bite test?

Answer 7

• frac finder or tooth sleuth
• cusps isolated and patient bites down
• pain on biting or release indicative of a crown fracture

Question 8

What are the endodontic treatment options?

Answer 8

• RCT
• re-RCT
• XLA
• KUO
• surgical intervention (peri-radicular surgery, NOT first line)

Question 9

What should you consider when deciding to re-RCT?

Answer 9

• diagnosis?
• risk/benefit analysis
• good reason to retreat?
• consent
• is tooth restorable? (can you place dam, ferrule)

Question 10

What guidelines have indications for re-RCT?

Answer 10

ESE

Question 11

What are the indications for re-RCT?

Answer 11

• teeth with inadequate RCT with radiographic finding of developing or persisting apical periodontitis, with/without symptoms
• teeth with inadequate RCT when the coronal restoration requires replacement or coronal tissue is to be bleached

Question 12

What is involved in the radiographic assessment of RCT?

Answer 12

• root filling quality (voids, length)
• unfilled or missed canals
• shape of canal
• patency (fractured instruments, posts)
• bone support
• crown root ratio
• pathology (not always visible)

Question 13

By how much does an MOD cavity weaken a tooth?

Answer 13

65%

Question 14

By how much does an MO cavity weaken a tooth?

Answer 14

33%

Question 15

What problems can arise during re-RCT?

Answer 15

• amount of remaining tooth structure
• restorability
• lack of ferrule
• wide post holes
• endodontic complications (fractured instruments, perforations, short/long fillings)

Question 16

What are the principles of restoring root treated teeth?

Answer 16

Consider cuspal protection
- good coronal seal to prevent ingress of bacteria
- prevention of fracture

Question 17

What are indications for restoring root treated teeth?

Answer 17

• coronal seal
• function
• aesthetics
• QoL

Question 18

What factors influence choice of restoration of root treated teeth?

Answer 18

• remaining tooth structure
• cost
• aesthetics
• patient preference
• chair time
• moisture control

Question 19

What fibre post system is used in GDH?

Answer 19

• DT light posts
• to be replaced by Rely X

Question 20

What is a core build up?

Answer 20

• internal part of tooth is built-up with restorative material to replace lost tooth tissue
• provides retention and resistance for definitive restoration

Question 21

Are posts indicated in posterior teeth?

Answer 21

• typically no
• requires long straight canal (often distal root of lower 6 or palatal of upper)

Question 22

How does moisture control influence restoration choice of root treated teeth?

Answer 22

• if composite could not be placed due to moisture control then cement used in onlay placement would also leak
• if above true, crown preparation should be undertake, despite increase in tooth tissue lost