Restoration of the Endodontically Treated Tooth

Question 1

what should you look for in a clinical assessment of an endodontically treated tooth

Answer 1

coronal seal
amount of remaining tooth structure
is the tooth restorable
swelling
sinus
TTP
buccal sulcus
mobility

Question 2

what should you be looking for on the radiograph of an endodontically treated tooth

Answer 2

root filling - length, quality
unfilled/ missing root canals
shape of canal
patency
bone support
crown to root ratio

Question 3

how often should you follow up with PA assessment of a RCT tooth

Answer 3

every year

Question 4

how often should you follow up with PA assessment of a RCT tooth

Answer 4

every year

Question 5

what are the problems after RCT

Answer 5

massive loss of dentine and tooth structure - internally and externally
wide post holes
fractured instruments/ perforations/ curved canals

Question 6

what is ferrule

Answer 6

no tooth preparation above the gum - 2mm of dentine above gingivae

Question 7

are RCT teeth more likely to fracture

Answer 7

because there is a massive loss of dentine they are more likely to fracture

Question 8

are RCT teeth as hard as non-root treated teeth

Answer 8

dentine hardness is not altered

Question 9

does dehydration affect the hardness of a RCT tooth

Answer 9

no it doesnt weaken strength or toughness

Question 10

what is coronal microleakage

Answer 10

ingress of oral-microorganisms into root canal system

Question 11

what should happen generally to root filled teeth that are left unrestored for 3 months

Answer 11

they should be re-root canal treated

Question 12

how do you create a coronal seal

Answer 12

trim GP to the access cavity and place RMGI over pulp floor and root canal openings

Question 13

if its a small access cavity (eg lingual/ palatal of anteriors)

Answer 13

composite restorations

Question 14

what restoration would be required for an anterior tooth missing marginal ridges

Answer 14

post crown

Question 15

what is the main indication for direct post restorations

Answer 15

ferrule present

Question 16

what is an indication for cast post and cores

Answer 16

no ferrule - no dentine above the gum level

Question 17

what is a disadvantage of doing a cast post crown on a tooth with no dentine above the gum level

Answer 17

its not stable and can rock when patients bite and can loosen the cement and cause bacteria ingress

Question 18

what is a post/ core

Answer 18

gains intraradicular support for a definitive restoration
the core provides the retention for a crown
post retains the core

Question 19

do posts strengthen or reinforce the tooth

Answer 19

no preparation of the root canal for a post weakens the tooth

Question 20

what is the post

Answer 20

placed in the root canal

Question 21

what is a core

Answer 21

what the prosthesis is cemented to - eg crown or bridge abutment

Question 22

what is required for post placement

Answer 22

incisors and canines
avoid in mandibular incisors due to thin roots
avoid in curved canals to avoid perforations

Question 23

what is the root filling length for post placement

Answer 23

4-5mm apically

Question 24

what should the width of the post be

Answer 24

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

Question 25

how much alveolar support is needed for a post

Answer 25

at least half of the post length into the root

Question 26

what is the requirements for a ferrule

Answer 26

at least 1.5mm height and width of remaining coronal dentine

Question 27

how is a ferrule described

Answer 27

dentine collar

Question 28

what are the advantages of retaining a ferrule

Answer 28

prevents tooth fracture prevents root fracture

Question 29

why should posts be parallel sided

Answer 29

avoids wedging in the tooth more retentive than tapered

Question 30

why should posts be non-threaded

Answer 30

smooth surface incorporated less stress to remaining tooth than threaded

Question 31

why should posts be cement retained

Answer 31

less retentive than threaded posts but cement acts as buffer between masticatory forces and post/ tooth

Question 32

what are the three classifications of posts

Answer 32

manufacture material shape

Question 33

what is the manufacture class of posts

Answer 33

pre-formed/ pre-fabricated or custom made

Question 34

what materials are used to make posts

Answer 34

cast metal, steel, zirconia, carbon/ glass fibre

Question 35

what shapes can pots be

Answer 35

parallel sided or tapered

Question 36

what are the classifications of pre-fabricated posts

Answer 36

tapered smooth tapered serrated tapered threaded parallel smooth parallel serrated parallel threaded

Question 37

what are advantages of using prefabricated posts

Answer 37

only 1 visit required no impression and lab visit required chairside core build up

Question 38

what are custom posts

Answer 38

cast from direct pattern fabricated in patient's mouth

Question 39

how is a custom post manufactured

Answer 39

unified post and core made in one piece with the same material

Question 40

what are the properties of a metal post material

Answer 40

poor aesthetics, root fracture, corrosion, cant use if patient has nickel sensitivity, radiopaque on radiographs

Question 41

what are the properties of ceramic post materials

Answer 41

high flexural strength and fracture toughness, favourable aesthetics, difficult retrievability and root fracture common

Question 42

what are the properties of fibre post materials

Answer 42

flexible, similar properties to dentine, aesthetic, retrievable, bond to dentine with DBAs, radiolucent

Question 43

what s a core build up

Answer 43

the internal part of the tooth is build up with restorative material to replace the lost tooth tissue

Question 44

what does the core build up provide

Answer 44

retention and resistance for definitive restorations

Question 45

what are the three common core materials

Answer 45

composite amalgam glass ionomer

Question 46

what are the properties of using composite as a core material

Answer 46

tooth coloured, good aesthetics, bonds to tooth structure, technique sensitive, moisture control required

Question 47

what type of post is a composite core usually used with

Answer 47

fibre post

Question 48

why are amalgam cores tended to be avoided

Answer 48

retention is required and poor aesthetics and have to leave for 24 hours to set

Question 49

why are glass ionomer cores not favourable

Answer 49

absorb water and core expands in size

Question 50

what is a Nayyar core

Answer 50

they cut a bit of the coronal GP away and replace it with amalgam to increase retention

Question 51

what is the difference between inlay and onlay

Answer 51

inlays - the cusps are not covered or supported whereas with onlays the cusps are supported

Question 52

how to determine if a tooth needs a post

Answer 52

could you build up a core does the tooth need a post now

Question 53

what factors should you consider when designing the restoration post RCT

Answer 53

how long will post be have you got a ferrule how wide 3-5mm remaining GP is canal straight how much space needed for the core

Question 54

what degree of taper should you have in your canal

Answer 54

6 degree

Question 55

how do you fit a post

Answer 55

do not fill post space with cement use firm apical pressure get rid of excess ask lab for provisional acrylic crown

Question 56

name four problems with posts

Answer 56

perforation core facture root fracture or crack post fracture

Question 57

what is the management for post perforation

Answer 57

repair - internal or external (periradicular surgery) extraction

Question 58

how are posts removed

Answer 58

ultrasonics masseran kit eggler moskito forceps

Question 59

what are the reasons by percentage why posts fail

Answer 59

60% due to restorative reasons 32% due to periodontal problems 8% due to endodontic reasons

Question 60

do all RCT teeth need a post and crown

Answer 60

no - can do onlay or composite build up

Question 61

why are unified post and core preferred for non vital teeth

Answer 61

it avoids material interfaces

Question 62

do all cores need a post

Answer 62

no