9. Endo Treated Teeth II

Question 1

What are the restorative options for an endo treated tooth

Answer 1

• Simple restoration
• Post and core
• Post core and crown

Question 2

What teeth with MOD amalgams have the highest fracture rate

Answer 2

maxillary premolars

Question 3

Reading slide 4

Answer 3

ok

Question 4

RCT teeth without crowns lost at _ times the rate of those with crowns

Answer 4

6x

Question 5

What teeth had the worst survival rate after RCT after 10 years

Answer 5

2nd molars (higher occlusal forces- near the fulcrum or the TMJ)

Question 6

What effect did the presence of proximal contacts have on RCT survival rates

Answer 6

teeth with 2 proximal contacts had better survival than 1 or none

Question 7

What are RCT teeth considered weaker than vital teeth -

Answer 7

• Less moisture (9% less in RCT)
• Less dentin strength (may be decreased)
• Less flexibility (bend and return to original shape)
• Dentin collagen changes
• Decreased amount of dentin= less strength**

Question 8

What are the main considerations when determining if a tooth needs a post or not

Answer 8

• Quanity of remaining tooth structure (aka ferrule**)
• Functional load on the tooth
• Shape of canal(s)

Question 9

What factor most determines the long term success of endo treated teeth

Answer 9

-Quanity of remaining tooth structure

Question 10

Describe the ferrule effect

Answer 10

• Apical extension of the finish line beyond the junction of the foundation and remaining tooth structure
• Allows the crown to engage the axial tooth structure which provides better stress distribution that reduces the potential for fracture

Question 11

The presence of adequate _ will often increase the likelihood that failures will be restorable rather than catestrophic

Answer 11

ferrule

Question 12

For adequate ferrul the presence of healthy dentin should extend - mm _ to the margin of the crown circumferenctially

Answer 12

1.5-2mm coronal

Question 13

Why is it that adequate ferrule decreases the likelihood of catestrophic failure

Answer 13

because ferrule distribute the load to the coronal tooth structure

Question 14

What are the safe minimums for ferrule

Answer 14

Vertical height= 1.5- 2mm
Thickness= 1 mm
**Needs to be 360 degrees to have the ferrule effect

Question 15

All forces on a crown are transmitted to

Answer 15

the post and root (consequences= post dislodgement and root fracture)

Question 16

T/F it is unclear as to whether or not crown lengthening improves the prognosis of the tooth

Answer 16

T because while it increases you failure (increases chances of success) it also increases the crown:root ratio (worse prognosis)

Question 17

When do you need a post

Answer 17

-The remaining tooth structure is not enough to retain the foundation

Question 18

Does a post reinforce/strengthen the tooth and increase RCT longevity

Answer 18

no

Question 19

Why does a post weaken a tooth

Answer 19

-Canal prep removes more dentin

Question 20

Anterior teeth are subjected to (more/less) force than posteriors

Answer 20

less

Question 21

What is typically the restoration for an anterior RCT

Answer 21

restoration of the endo access- often do not need FCR Especially when the marginal ridges are intact and the dentin supports all enamel

Question 22

Anterior functional forces occur on a relatively _ surface

Answer 22

flat

Question 23

Is a post generally required for anterior teeth

Answer 23

no- only if there is significant loss of coronal tooth structure

Question 24

Anterior RCT is discolored what are more conservative ways to improve the esthetics

Answer 24

• Internal bleeching

- Veneer

Question 25

T/F A cemented post offers reinforcement

Answer 25

f

Question 26

T/F Incisors can tolerate higher loads without posts than those with posts

Answer 26

t

Question 27

If 50% of the clinical crown remains for an anterior tooth what are the treatment options (rank the choices)

Answer 27

1. Prefab post with a resin core 2. One piece custom cast post and core 3. Foundation only no post (unlikely) * *Full coverage restoration required

Question 28

In order to provide maximum support for the resin core the post should extend

Answer 28

to the incisal reduction

Question 29

When most/all of the clinical crown of an anterior tooth is missing rank the different treatment options

Answer 29

1. One peice custom cast post and core 2. Pre-fab post and resin core * *Full coverage restoration required

Question 30

Incidactions for custom cast post and cores are

Answer 30

- Extensive loss of coronal tooth structure | - Wide flared canals

Question 31

What is the most important prognostic factor

Answer 31

ferrule effect

Question 32

Posterior forces are subject to more force because they are closer to what

Answer 32

the condyles

Question 33

Why is it that full coverage restorations are often recommended for posterior RCT teeth

Answer 33

-Functional forces in the posterior act to "wedge" the cusps apart (this is sig. increased in RCT teeth)

Question 34

Full coverage restorations are only recommended for anterior teeth when

Answer 34

They are structurally weakened by large or multiple restorations

Question 35

What is the exception to placing a full coverage restoration on posterior RCT teeth

Answer 35

- Mandibular first PM (the lingual cusp is out of occlusion and there in no wedging effect) - Bicuspids with minimal loss of tooth structure (1/2 or more of the clinical crown remains)

Question 36

When 1/2 or more of a bicuspid clinical crown remains what are the ranked order of treatment options

Answer 36

1. Pre-fab post with amalgam or resin 2. One piece cast post and core * *Full coverage restoration required

Question 37

Extensive loss of tooth structure for premolars- what are the ranked options for tx

Answer 37

1. One piece cast post and core 2. Pre-fab post with amalgam or resin * *Full coverage restoration required

Question 38

What are the potential clinical failure associated with a pre-fab post and amalgam/resin core

Answer 38

- Material separation | - Post fracture

Question 39

What is the recommended treatment for a RCT molar with minimal loss of tooth structure

Answer 39

-This is rare- all cusps present and supported by dentin with both marginal ridges intact ``` Foundation required (amalgam or resin) post may be required -Full coverage resoration suggestted ```

Question 40

Describe what an EndoCore is

Answer 40

-Coronoradicular amalgam This is an alternative to post placement -Condensation of amalgam in the available canals (2-4mm)

Question 41

What provides the retention for for the endoCore

Answer 41

The divergence of the canals

Question 42

EndoCore is indicated when

Answer 42

- At least 3 dentin walls (> or equal to 1 mm thick) are present around the pulp chamber - Adequate dentin to retain the core - Post not needed

Question 43

What is the recommended treatment for a RCT molar with moderate loss of tooth structure (1-2 cusps missing or 1 marginal ridge missing)

Answer 43

Foundation required and pins as needed | FCR

Question 44

What is the recommended treatment for a RCT molar with extensive loss of tooth structure

Answer 44

Foundation required + pre-fab/cast post | FCR required