Restoration of Endodontically Treated teeth

Question 1

What do you assess on an endodontically restored tooth?

Answer 1

Coronal seal
Amount of remaining tooth structure
Swelling
Sinus
TTP
Tender soft tissues
Mobility
Increased pocketing

Question 2

What do you look for on a radiograph when assessing a root treatment?

Answer 2

Unfilled/missed root canals
Shape of canal
Bone support
Crown to root ratio
Apical pathology

Question 3

What are the restorative problems faced after RCT?

Answer 3

Amount of remaining tooth structure
Lack or no ferrule
Wide post holes
Endo complications (Fractured instruments)

Question 4

Are teeth brittle after endodontic treatment?

Answer 4

No

Question 5

Are root treated teeth more prone to fracture?

Answer 5

No

Question 6

Is dentine hardness affected after RCT?

Answer 6

No

Question 7

Does dehydration affect the hardness of a RCT tooth?

Answer 7

No

Question 8

What is coronal microleakage?

Answer 8

Ingress of microorganisms into root canal system

Question 9

What can coronal microleakage cause?

Answer 9

Infection of the apical tissues
Failure of RCT

Question 10

How do you create a good coronal seal

Answer 10

Trim GP to the ACJ and place RMGI over pulp floor and root canal openings.

Question 11

What restorations could you give for an anterior tooth with intact marginal ridges?

Answer 11

Porcelain/composite veneer

Question 12

What restoration could you give for anterior teeth with intact marginal ridges and discoloured crown?

Answer 12

Bleaching or veneer crown

Question 13

What restoration could you give for anterior tooth with marginal ridges destroyed?

Answer 13

Core build up for crown
Post crown

Question 14

What prep modificaiton is required for a direct post?

Answer 14

A ferrule

Question 15

What does a post/core do?

Answer 15

Gain intraradicular support for definitive restoration, and provides retention for crown retains the core.

Question 16

When do you avoid placing a post/core?

Answer 16

If sufficient coronal dentine present mandibular incisors (thin roots) curved canals (avoid perforations)

Question 17

Wow long should the root filling length be when placing a post?

Answer 17

4-5mm apically

Question 18

How wide should the post be for a post crown?

Answer 18

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

Question 19

What should the minimum post length to crown ratio be?

Answer 19

1:1

Question 20

How much ferrule do you need for a post/core crown?

Answer 20

1.5mm height and width

Question 21

What is a ferrule?

Answer 21

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

Question 22

What is the purpose of a ferrule?

Answer 22

Lowers risk of root fracture and increases crown retention.

Question 23

When is the risk of root fracture significantly increased

Answer 23

If a crown margin is not placed onto solid tooth

Question 24

How can you achieve a ferrule if there there is not enough coronal dentine?

Answer 24

Orthodontic extrusion or crown lengthening

Question 25

How deep should a post go for a post crown?

Answer 25

At least halfway down the root to ensure good alveolar bone support

Question 26

What is the ideal post in a post crown?

Answer 26

Parallel sided Non-threaded Cement retained

Question 27

What does a parallel sided post avoid?

Answer 27

Wedging

Question 28

What does a non-threaded post allow?

Answer 28

Less stress to remaining tooth structure

Question 29

What categories are post crowns classified into?

Answer 29

Manufacturer Material Shape

Question 30

What are the different types of manufactured post crowns?

Answer 30

pre-formed or custom made

Question 31

What are the materials available for post crowns?

Answer 31

Cast metal Steel Zirconia Carbon/glass fibre

Question 32

What are the shapes that a post crown can have?

Answer 32

Parallel sided or tapered

Question 33

What are the advantages of prefabricated posts?

Answer 33

Only 1 visit required No impressions or lab needed Chairside core build up Immediate preparation of core Large selection of designs and materials

Question 34

How are custom posts made?

Answer 34

Impressions/casts from patients mouth

Question 35

Typically how many visits are needed for custom posts?

Answer 35

2

Question 36

What material are cast posts made in?

Answer 36

Type 4 heat hardened gold

Question 37

What are the properties of metal posts?

Answer 37

Poor aesthetics Lower root fracture risk Corrosion resistant Radiopaque

Question 38

What are the properties of ceramic posts?

Answer 38

High flexural strength and fracture toughness Favourable aesthetics Difficult retrievability Root fracture more common

Question 39

What are the properties of fibre posts?

Answer 39

Flexible Similar mechanical properties to dentine Aesthetic Retrievable Bond to dentine with DBA Radiolucent

Question 40

What is a core build up?

Answer 40

Internal part of tooth built up with restorative material to replace lost tooth tissue

Question 41

What does the core of a core build up provide?

Answer 41

Retention and resistance for definitive restorations

Question 42

What materials are used for core build ups?

Answer 42

Composite Amalgam Glass ionomer

Question 43

What is a nayyar core?

Answer 43

RCT removed from canals amalgam packed into canals, then tooth built up

Question 44

What considerations do you need to think of when deciding what restoration to choose?

Answer 44

How long the post is Is there a ferrule How wide is the post Is there 3-5mm remaining GP in canal How straight is the canal How much space for the core

Question 45

How much taper is needed for a core?

Answer 45

6 degree

Question 46

How much GP is left in apical third of canal?

Answer 46

3-5mm

Question 47

How do you remove GP for a post crown?

Answer 47

Dental dam Gates gliddens size 3 Working length and rubber stop

Question 48

How much space should be left in the occlusion when a crown is placed?

Answer 48

2mm

Question 49

What is the process for trying in a post?

Answer 49

Irrigate with chlorhexidine Dry with paper points Ensure fits around prep Ensure enough occlusal clearance

Question 50

What complications can arrise from posts?

Answer 50

Perforation Core fracture Root fracture Crack/fracure in post

Question 51

How would you manage a post perforation?

Answer 51

Repair internally or extract the tooth.

Question 52

What can be used to remove a post

Answer 52

Ultrasonics Masseran kit Moskito forceps

Question 53

What are the reasons for post failure?

Answer 53

Restorative reasons Periodontal problems Endodontic reasons Heavy occlusal load/abnormal occlusion