Coronal Leakage Flashcards
Maximum tooth fragility is endo tooth with…
MOD
1mm ferrule impact on fracture resistance?
doubles compared to no ferrule
Coronal restoration main goal
prevent microleakage
Where does microleakage occur
gaps between tooth structure and restorative materials
Timespan of microleakage of endo treated tooth without restoration?
3-90d
Microleakage minimized by rubber dam?
yes
Good Endo with good restoration =
Good Endo with bad restoration =
Bad Endo with good restoration =
Bad Endo with bad restoration =
Good Endo with good restoration = 91%
Good Endo with bad restoration = 44%
Bad Endo with good restoration = 67%
Bad Endo with bad restoration = 18%
Coronal vs Radicular microleakage?
coronal - restorative material and tooth
radicular - post/filling and root
6 steps of endo protocol
- Pros consult to determine if can restore
- Recept PA and BW radiographs
- Endo tests
- Pulpal diag
- periapical diag
- endo recommendation (UG OR PG)
Impact of coronal restoration on prognosis for endo teeth for anterior? post?
anterior - greatly improves
Post - not
Restorative materials for
Cavit and IRM
3mm
Restorative materials for > 3wk?
composite resin or RMGI
What do posts do?
Reinforce teeth? When not necessary?
Retain final restoration
Do not reinforce, not necessary when sufficient structure present
Use of rubber dam vs no use success %
dam - 93.3%
no dam - 73.6%
Post placement: dentin removal? minimum GP apically length vs root length vs crown width vs root relationship vs crest of bone?
minimize removal of dentin
5mm GP
1/2 length of root in bone
1 and 1/3 length of crown, longer than crown - should be as long as possible without disturbing apical 5mm GP
1/3 width root in bone, 1mm dentin minimum
extend post-apical of crest of bone
Impact on elastic modulus on root fracture?
want it to be similar - will dissipate
if post is higher modulus - will focus at apex –> fracture
Risk of root perforation increases when doing what when placing posts?
severe alteration of natural shape of canal
Post diameter vs…
retention
fracture
perforation
no effect
increases
increases
When is core indicated (2)?
- replacement of missing coronal structure
2. resistance
Disadvantages of composite and amalgam?
composite - leaking due to shrinkage
amalgam - no adhesion to tooth structure
Crown indicated when?
better esthetics, or when structural integrity of natural tooth compromised
Minimum ferrule?
1-2mm
Purpose of ferrule?
Resists fracture, horizontal movement, increases retention
What to do if need RTC on an existing crown with caries?
remove crown and caries first
