Chapter 40 - Restoration of Endodontically Treated Teeth Flashcards
Should crowns be placed on endodontically treated teeth?
Yes. Especially posterior teeth
Do posts improve long term clinical prognosis/ enhance strength?
No. Post provides RETENTION for a core.
What is clinical failure rate of post & core?
7-14% (8 yrs study)
Most types of post & core failures?
Loss of retention & fractures
Which post design creates greatest & least retention?
Threaded is the greatest
Tapered is the least
Is there any relationship between post form & root fracture?
Yes. Threaded post produce the greatest potential of root fractures
What is the proper length for a post?
3/4 length of the root (long rooted)
min 5 mm gutap for average tooth
post minimum extended 4 mm to apical bone crest to decrease dentin stress
molar post shouldn’t be extended to root canal apical more than 7 mm
How much gutta percha should be retained to preserve the apical seal?
4-5 mm
Does post diameter affect retention and potential root fracture?
Increase diameter = increase stress
What is the relationship between post diameter & root perforation?
Post diameter = root dimension
small teeth = 0.6 - 0.7 diameter instrument
large teeth = 1-1.2 mm
Can gutta percha be removed immediately after RCT?
Yes
How soon should the definitive restoration be placed after post space prep?
Right after prep. providing functional & aesthetics, provide hard & soft tissue protection
Does cervical ferrule helps prevent tooth fracture?
Yes. Min 2 mm.
Minimum dentin thickness after RCT
1 mm
Type of posts
Custom
Prefabricated: parallel, tapered, smooth, serrated (pasive)., threaded (active)
Carbon fiber reinforced epoxy resin properties?
high fatigue strength, high tensile strength, modulus elasticity similar to dentin. Adequate physical properties vs metal.
When ferrule is small/ absent, CFR may cause post to flex, causing a micromovement of entire core»_space; microleakage»_space; fluids & bacteria»_space; failure
Glass fiber reinforced epoxy resin posts properties?
shape : cylindrical/ conical / cylindroconical
high fatigue strength, high tensile & modulus elasticity closer to dentin vs CFR
Polyethylene fiber reinforced post usage?
Large canal»_space; ribbons shape > follows canal shape
Zirconia post properties?
Tetragonal zirconiums polycristal (TZP) used in dentistry
high flexural strength & fracture toughness. low solubility
