Dr. Conn 1 Flashcards Preview

week 49 > Dr. Conn 1 > Flashcards

Flashcards in Dr. Conn 1 Deck (35)
Loading flashcards...
1

Endo treated tooth: majority of failures due to

  • inadequate restoration followed by tooth loss due to perio
  • few teeth are lost due to endo

2

Success rate of treatment for general dentists vs endo?

  • General=65-75%
  • Endo=70-95%

3

Orthograde contamination

  • Failure mechanism
  • contamination via leakage of oral fluids apically within root

4

Coronal Sealing

  • done as soon as possible after root canal is finished

5

Factors to place a post in a tooth

  • position of the tooth in the arch
  • occlusion
  • function of the restored tooth
  • amount of remaining tooth structure
  • canal configuration

6

reasons for placing a post

  • old Assumption:
    • strengthen the root of a endo treated tooth
  • Todays assumption:
    • retain the core buildup material 
    • reinforce remaining coronal tooth

7

Post types

  • Custom cast posts
  • Pre-fabricated posts
    • metallic posts
    • non-metallic posts (tooth colored)

8

What does increased post length result in?

  • Results in:
    • increased retention
    • restistance to fracture

9

Posts: most Retention to least

  • Most to least retention
    • active posts
    • parallel posts
    • tapered post=least

10

Posts: Most conservative to least

(of tooth structure)

  • Most
    • tapered 
    • parallel
    • active
  • least

11

How to choose the right post

  • most conservative post
  • adequate rentention
  • without compromising fracture resistance of the root

12

Does a post strengthen a tooth?

it Depends

  • Fracture resistance 
    • of the root descreases with post placement

13

Indications for custom cast post and core

  • multiple posts and cores
  • cores for smaller teeth
  • changing the orientation of the core to post

14

Parallel Posts characteristics

  • Passive parallel posts
    • intermediate
      • retention 
      • conservation

15

indications for Parallel posts 

  • parallel canal prep 
  • large diameter root at the tip of the post
  • need increased retention

16

Examples of parallel posts

  • Parapost Plus
  • BCH
  • Unity
  • Boston Post

17

Tapered posts characteristics

  • Least retentive
  • most conservative 

18

Indications for Tapered Posts

  • 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

Examples of tapered posts

  • Endowel
  • Filpost

20

Star Endowel Post

  • 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

Active Posts characteristics

  • Greatest retention
  • Least conservative
  • increase stresses to the tooth

22

Indications for Active Posts

  • post space length minimal
    • short clinical roots 
    • Canal space obstructed
  • Funnel shaped canal

23

Examples of Active Posts

  • Flexipost
  • V-Lock
  • Radix
  • Cytco

24

Advantages of Non-Metallic posts

  • 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