Dr. Conn 1 Flashcards
1
Q
Endo treated tooth: majority of failures due to
A
- inadequate restoration followed by tooth loss due to perio
- few teeth are lost due to endo
2
Q
Success rate of treatment for general dentists vs endo?
A
- General=65-75%
- Endo=70-95%
3
Q
Orthograde contamination
A
- Failure mechanism
- contamination via leakage of oral fluids apically within root
4
Q
Coronal Sealing
A
- done as soon as possible after root canal is finished
5
Q
Factors to place a post in a tooth
A
- position of the tooth in the arch
- occlusion
- function of the restored tooth
- amount of remaining tooth structure
- canal configuration
6
Q
reasons for placing a post
A
- old Assumption:
- strengthen the root of a endo treated tooth
- Todays assumption:
- retain the core buildup material
- reinforce remaining coronal tooth
7
Q
Post types
A
- Custom cast posts
- Pre-fabricated posts
- metallic posts
- non-metallic posts (tooth colored)
8
Q
What does increased post length result in?
A
- Results in:
- increased retention
- restistance to fracture
9
Q
Posts: most Retention to least
A
- Most to least retention
- active posts
- parallel posts
- tapered post=least
10
Q
Posts: Most conservative to least
(of tooth structure)
A
- Most
- tapered
- parallel
- active
- least
11
Q
How to choose the right post
A
- most conservative post
- adequate rentention
- without compromising fracture resistance of the root
12
Q
Does a post strengthen a tooth?
A
it Depends
- Fracture resistance
- of the root descreases with post placement
13
Q
Indications for custom cast post and core
A
- multiple posts and cores
- cores for smaller teeth
- changing the orientation of the core to post
14
Q
Parallel Posts characteristics
A
- Passive parallel posts
- intermediate
- retention
- conservation
- intermediate
15
Q
indications for Parallel posts
A
- parallel canal prep
- large diameter root at the tip of the post
- need increased retention
16
Q
Examples of parallel posts
A
- Parapost Plus
- BCH
- Unity
- Boston Post
17
Q
Tapered posts characteristics
A
- Least retentive
- most conservative
18
Q
Indications for Tapered Posts
A
- Tapered root/canal obturation in roots with thin tapered canals
- maxillary
- premolar
- lateral incisors
- mandibular incisors
- Adequate length is present (7-8mm)
- Canal is not over enlarged
19
Q
Examples of tapered posts
A
- Endowel
- Filpost
20
Q
Star Endowel Post
A
- Tapered post
- plastic patterns used in custom cast post and core
- cast by removable lab in chromium-cobalt alloy
- inexpensive prefabricated tapered post
- Gates Gliddents fit the endowel sizes
- Mechnical retention must be cut into the endowel before cementation
21
Q
Active Posts characteristics
A
- Greatest retention
- Least conservative
- increase stresses to the tooth
22
Q
Indications for Active Posts
A
- post space length minimal
- short clinical roots
- Canal space obstructed
- Funnel shaped canal
23
Q
Examples of Active Posts
A
- Flexipost
- V-Lock
- Radix
- Cytco
24
Q
Advantages of Non-Metallic posts
A
- MOE similar to dentin
- good for tooth
- bad for core materials
- Esthetic=tooth colored
25
Examples of Non-metallic posts
* Carbon fiber posts=OUT
* radiolucent
* can't remove
* Zirconium
* not recommended
* rigid and brittle
* can't bond effectively
* very difficult to remove
* Composite fiber posts-YES
26
How do I choose a post?
* Retention Triad
27
Resistance
* Prevent dislodgement or fracture by compressive forces
* Resistance features of restoration not met=high fail probablity
* Crown Bevil
* most important resistance feature of restoration
* part of crown margin
* extends past the post and core margin onto natural tooth
* Vertical Remaining tooth affects resistance
* no longer flatten face of tooth for post buildup
* Antirotation
* important component of resistance
28
Resistance Triad
* Resistance Form
* Antirotation
* oblong canal orifice
* keyways
* pins
* Crown Bevel
* effective if it:
* encirlces the tooth
* extend onto tooth structure at least 2 mm below post and core margin
* Vertical Remaining tooth structure
* leaving as much vertical tooth structure increases the resistance
29
Retention form is affected by:
* Post Length
* Luting Agent (Cement)
* Post style
30
Luting Agents (Cements)
* Cement=least important part of retention triad
* Increased usage of resin cements
31
Resin Cement: Advantages vs disadvantages
* Advantages:
* low solubility
* high modulus of elasticity
* quick setting
* bonds to post and dentin
* Disadvantage
* technique sensitive
* Doesn't bond to post or root dentin
32
Indications for Post placement in Anterior Teeth
* experience mostly shear forces
* different than posterior teeth
* Maxillary Centrals & Canines
* fxn of tooth
* amount of coronal tooth structure
* Intact anterior tooth w/conservative endo access
* DOES NOT require a POST or coronal coverage
33
Indications for Post placement in Posterior Teeth
* Require cuspal coverage (except mandibular 1st molar)
* Molars not crowned
* lost at 6x greater rate
* Premolars not crowned
* lost at 5.8x greater rate
* Premolars-requires judgement
* Consider:
* tooth morphology
* tooth fxn
* post indicated when:
* serves as abutment
* lateral stress
* Clinical crown height is taller than the diameter at the CEJ
34
Chamber Retention Buildup
* Aka Amalcore
* Very effective
* Post in molar teeth only required for retention of buildup material
* Post not indicated when other less invasive procedures can be used
* chamber retention
* pins
* amalgam pins
* adhesives
* If less than 4mm
* helps to go into canal space
35
Complex Post Buildups
* Molars
* Only 1 post in the large canal
