Endo/Rest: Restoration of Endodontically Treated Tooth

Question 1

What is the biggest cause of RCT failure ?

Answer 1

Coronal micro leakage caused by poor coronal seal.

Question 2

Your patient has an root treated anterior tooth with intact marginal ridges - what are the treatment options for restoring this tooth ?

Answer 2

Composite restoration or veneer.

Question 3

Your patient has an root treated anterior tooth with intact marginal ridges but is discoloured - what are the treatment options for restoring this tooth ?

Answer 3

Bleaching or veneer or crown.

Question 4

Your patient has a root treated anterior tooth with loss of the marginal ridge - what are the treatment options for restoring this tooth ?

Answer 4

Core build up with crown or post-crown.

Question 5

What are the functions of a post-core ?

Answer 5

Gains intra-radicular support for a definitive restoration.
Core provides retention for crown.

Question 6

What are the guidelines for placing a post with regard to tooth type/selection ?

Answer 6

Incisors and canines - unnecessary if sufficient coronal dentine.
Contraindicated in mandibular incisors.
Avoid in dilacerated canals.

Question 7

Guidelines for post placement - how much root filling should be left after post placement ?

Answer 7

4-5mm.

Question 8

RESTORATION OF ENDODONTICALLY TREATED TOOTH

Guidelines for post placement - how wide should your post be ?

Answer 8

No more than 1/3 root width at narrowest point and 1mm of circumferential coronal dentine remaining.

Question 9

Guidelines for post placement - what is the post length/crown ratio ?

Answer 9

1:1

Question 10

Guidelines for post placement - what is the minimum ferrule required for post-placement ?

Answer 10

1.5mm

Question 11

Define ferrule.

Answer 11

Dentine collar - encirclement of 1-2mm of vertical axial tooth structure within the walls of a crown.

Question 12

What is the importance of a ferrule ?

Answer 12

Prevents tooth/root fracture.

Question 13

What are the characteristics of the ideal post ? And why ?

Answer 13

Parallel sided - avoids wedging and more retentive.
Non-threaded - incorporates less stress.
Cement retained - acts as buffer between masticatory forces and post-tooth.

Question 14

MANUFACTURE - what are the benefits of a pre-fabricated post ?

Answer 14

1 visit required for post prep and placement.

Question 15

MANUFACTURE - what are the benefits of a custom post ?

Answer 15

Unified post and core - made of one piece of same material.

Question 16

MANUFACTURE - what is the disadvantages of a custom post ?

Answer 16

2 appointments required.
Temporisation between visits.
Risk of contamination.

Question 17

MATERIAL - what metals are used in fabrication of post ?

Answer 17

Cast gold, stainless steel, brass, titanium.

Question 18

MATERIAL - what are the disadvantages of using metal post ?

Answer 18

Poor aesthetics, risk of root fracture, corrosion, sensitivity.

Question 19

MATERIAL - what is the benefits of using metal post ?

Answer 19

Radiopaque.

Question 20

RESTORATION OF ENDODONTICALLY TREATED TOOTH

MATERIAL - what two ceramics can be used in fabrication of post ?

Answer 20

Zirconia or alumina.

Question 21

MATERIAL - what are the benefits of using ceramic post ?

Answer 21

High flexural strength, fracture toughness, favourable aesthetics.

Question 22

MATERIAL - what are the disadvantages of using ceramic posts ?

Answer 22

Difficult retrievability and root fracture common.

Question 23

MATERIAL - what are the benefits of fibre post ?

Answer 23

Flexible, dentine properties, aesthetic, retrievable, bonds to dentine via DBA, radiolucent.

Question 24

MATERIAL - what is the disadvantage of fibre posts ?

Answer 24

Need substantial tooth tissue remaining.

Question 25

Tapered vs. parallel posts ?

Answer 25

Tapered are less retentive vs. parallel. Parallel posts are less conservative.

Question 26

What three materials can be used for core build up ?

Answer 26

Composite, amalgam, GI.

Question 27

What is the benefits of using composite for core build up ?

Answer 27

Good aesthetics, bonds to tooth structure, command set.

Question 28

What is the disadvantages of using composite for core build up ?

Answer 28

Moisture control.

Question 29

# RESTORATION OF ENDODONTICALLY TREATED TOOTH What type of post requires composite core build up i.e. indications for using composite as core material ?

Answer 29

Fibre post.

Question 30

What is the problems which using amalgam as core build up material ?

Answer 30

Poor aesthetics, cannot be prepared straight away, requires 24 hours to set, less retentive.

Question 31

What is the problems with using GIC are core build up material ?

Answer 31

Absorbs water and core expands in size - risk of crown not fitting.

Question 32

What is a Nayyar core ?

Answer 32

Amalgam packed into coronal part of root canals and tooth built-up. Provides retention for amalgam.

Question 33

What is the gold standard restoration of posterior endodontically treated tooth ?

Answer 33

Onlay cusps coverage restoration coverage for all cusps - reduces risk of cusps fracture. Other options - porcelain, gold, MCC crown, amalgam, restoration.

Question 34

What are the two key core design features ?

Answer 34

6 degree taper and 2mm clearance for MCC.

Question 35

There is sufficient coronal structure present - how is rotation prevented ?

Answer 35

Vertical coronal wall.

Question 36

# RESTORATION OF ENDODONTICALLY TREATED TOOTH There is absence of coronal dentine - how is rotation prevented ?

Answer 36

Vertical groove in canal acts as anti-rotational element.

Question 37

What are the risks related to posts ?

Answer 37

Perforation, core fracture, root fracture, post fracture, repeated debonding.

Question 38

What are the treatment options for a post perforation ?

Answer 38

Internal or external repair (periradicular surgery might be indicated). Extraction.

Question 39

What is the prognosis for a root treated tooth ?

Answer 39

7-10 years.

Question 40

How can root fractures be diagnosed ?

Answer 40

Periodontal exam looking for extended pockets. Bite tests using frac finders. Transillumination. Test cavities. Selective anaesthesia. Radiographs.

Question 41

Why should an endodontically treated tooth have a cusp coverage restoration ?

Answer 41

For good coronal seal and prevention of fracture.

Question 42

What luting agent is used to cement fibre post ?

Answer 42

RelyX - self adhesive universal resin cement.

Question 43

What luting agent is used to cement custom metal post ?

Answer 43

Aquacem.

Question 44

What are the two brand names of composites used for core build ups ?

Answer 44

SDR and Paracore.