13 - Endodontic interface Flashcards
What guidelines are used for endodontic diagnosis?
AAE
What are reasons that RCT teeth continue to be symptomatic?
- PDL
- bone
- microorganisms
- tooth not sterile
- lateral or accessory canals
What questions should you ask the patient when considering re-RCT?
- 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?
What is involved in an endodontic examination?
- EO
- IO
- STE
- swelling
- sinus tracts
- apical palpation
- percussion
- mobility
- periodontal exam
What does a long thin pocket indicate?
Vertical fracture
What special tests can be used?
- radiographs
- bite test
- test cavity
- staining/transillumination
- selective anaesthesia
What is a bite test?
- frac finder or tooth sleuth
- cusps isolated and patient bites down
- pain on biting or release indicative of a crown fracture
What are the endodontic treatment options?
- RCT
- re-RCT
- XLA
- KUO
- surgical intervention (peri-radicular surgery, NOT first line)
What should you consider when deciding to re-RCT?
- diagnosis?
- risk/benefit analysis
- good reason to retreat?
- consent
- is tooth restorable? (can you place dam, ferrule)
What guidelines have indications for re-RCT?
ESE
What are the indications for re-RCT?
- 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
What is involved in the radiographic assessment of RCT?
- 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)
By how much does an MOD cavity weaken a tooth?
65%
By how much does an MO cavity weaken a tooth?
33%
What problems can arise during re-RCT?
- amount of remaining tooth structure
- restorability
- lack of ferrule
- wide post holes
- endodontic complications (fractured instruments, perforations, short/long fillings)
What are the principles of restoring root treated teeth?
Consider cuspal protection
- good coronal seal to prevent ingress of bacteria
- prevention of fracture
What are indications for restoring root treated teeth?
- coronal seal
- function
- aesthetics
- QoL
What factors influence choice of restoration of root treated teeth?
- remaining tooth structure
- cost
- aesthetics
- patient preference
- chair time
- moisture control
What fibre post system is used in GDH?
- DT light posts
- to be replaced by Rely X
What is a core build up?
- internal part of tooth is built-up with restorative material to replace lost tooth tissue
- provides retention and resistance for definitive restoration
Are posts indicated in posterior teeth?
- typically no
- requires long straight canal (often distal root of lower 6 or palatal of upper)
How does moisture control influence restoration choice of root treated teeth?
- 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
