lecture 6- restoration of extensively damaged vital teeth

Question 1

central core guidlines

Answer 1

1. pulp and 1mm thick surrounding layer of dentin should be preserved if possible
2. retentive features should not be cut deeper than 1.5mm at cervical line or central fossa (2mm)
3. auxiliary retentive features ideally kept in “safe zone”
4. caries removal: depper areas filled with base

Question 2

shrinks and recedes as we age

Answer 2

central core (pulp chamber)

Question 3

5 categories involved in decision making

Answer 3

1. deciding on the type of restoration to use (crown, filing or other)
2. using defects as retentive features (do i need build up?)
3. pin placement and retention (will build up stay put?)
4. bases and cores (do i need to protect the pulp?)
5. tooth preparation procedures

Question 4

how to determine the type of restoration to use when large decay has destroyed tooth structure:

Answer 4

1. where is decay
2. how much tooth structure is remaining
3. where is remaining tooth structure
4. can i restore this
5. should i restore this

Question 5

extensive peripheral destruction=

Answer 5

full crown

Question 6

isthmus destruction greater than 1/2 intercuspal width=

Answer 6

crown or onlay

(less destructive central lesion)

Question 7

more than 50% of tooth structure is gone and loss of cuspal support=

Answer 7

crown and likely core build up too

(large central lesion)

Question 8

combined central and pheripheral destruction:

Answer 8

1. core build up and crown
2. possible RCT/Post/Core/Crown

Question 9

when would you decide you needed a root canal treatment

Answer 9

1. if pulp is exposed
2. post is needed for retention of build up

Question 10

deep proximal lesions impinging on vital core (central)

Answer 10

moderate damage to central tooth structure

Question 11

more than 50% of vital core destroyed (central)

Answer 11

severe damage to central tooth structure

Question 12

often, tooth prep will need to be modified by adding retentive features to increase retention and improve resistance form:

Answer 12

1. re-orientation of sloping surfaces
2. adding grooves
3. adding box forms
4. adding pins with a build up

Question 13

what we can do to increase resistance form with less than ideal tooth structure remaining

Answer 13

1. reshape acial walls to reduce convergence
2. add grooves
3. add box forms
4. increase wall height
   -place finish line more apical
   -pin retained core
   -crown-lengthening
   -orthodontic extrusion

Question 14

reshape axial walls to ________
(retention with axial wall)

Answer 14

reduce convergence

Question 15

increased axial reduction in cervical 1/2 of prep wall will

Answer 15

reduce taper and create more retention and greater resistance form

Question 16

sloping surfaces left after cusp fracture or caries removal need:

Answer 16

retention

Question 17

sloped wall retention: breaking slope

Answer 17

1. break slop into vertical and horizontal components
   conversion into one large vertical wall weakens tooth with too much removal and endangers the vital core of the tooth

Question 30

how can we get more wall height?

Answer 30

1. place margin more apically
2. add materials to build up the tooth
3. remove biological width restrictions with crown lengthening
4. pull tooth out of bone with orthodontic extrusion

Question 35

build up is needed when ______of the tooth structure is lost

Answer 35

more than 50%

Question 36

build up guidlines…
first reason for build up:
second reason for build up:

Answer 36

1: short axial wall
2. excessive interocclusal distance