Restoration of Endodontically Treated Teeth Flashcards
(33 cards)
1
Q
What does the clinical assessment of a tooth potentially requiring endodontic treatment include?
A
- potential for coronal seal
- current restorations and crowns
- leakage
- caries
- amount of remaining tooth structure
- ferrule
- restorability
- isolation with rubber dam
- swelling
- sinus
- TTP
- buccal sulcus
- TTP
- mobility
- increased pocketing
- periodontal disease
- root fractures
2
Q
What does the radiographic assessment of a tooth potentially requiring endodontic treatment include?
A
- root filling
- length
- quality of obturation (voids)
- unfilled/missing root canals
- shape of canal
- patency
- fractured instruments
- bone support
- mild
- moderate
- severe
- crown to root ration
- 1:1.5
- pathology
- periapical radiolucency
- resorption
- perforations
3
Q
For how long after completion of endodontic treatment should a tooth be monitored?
A
- 4 years
4
Q
What can happen as a result of re-treating inadequate root fillings?
A
- symptoms appear
- due to disturbance of microorganisms
- must re-treat before restoration placed
5
Q
What problems can occur after RCT?
A
- little remaining tooth structure
- internal and external
- usually significant loss of dentine, structure undermined
- functional and aesthetic restoration can be challenging
- lack or no ferrule
- wide post holes
- on re-treatment
- endodontic complications
- fractured instruments
- perforations
- short/long root fillings
6
Q
What is a ferrule?
A
- 1-2mm collar of dentine extending above the gingival level
- prevents tooth fracture
- if crown margin not on solid tooth, risk significantly increased
- braced at neck of tooth
7
Q
What are the properties of RCT teeth?
A
- prone to fracture due to lack of dentine
- minimal access cavities rare in Scotland
- same hardness and brittleness as untreated teeth
8
Q
What is coronal microleakage?
A
- ingress of oral micro-organisms into the root canal system
- infection, even though tooth non-vital, in PDL and bone
- important cause of RCT failure
- significant in multi-rooted teeth
- RCT teeth unrestored for >3 months should be re-RCT
9
Q
What can be done to prevent coronal microleakage?
A
- trim GP to the access cavity
- place RMGI over pulp floor and canal openings
- not too thick
- allows remainder of pulp chamber for retention of restoration
10
Q
What can be done to prevent coronal microleakage?
A
- trim GP to the access cavity
- place RMGI over pulp floor and canal openings
- not too thick
- allows remainder of pulp chamber for retention of restoration
11
Q
What are the restoration options for RCT anterior teeth?
A
- composite restoration
- anterior teeth with intact marginal ridges
- veneer
- anterior teeth with intact marginal ridges
- anterior teeth with intact marginal ridges and discoloured crown
- bleaching
- anterior teeth with intact marginal ridges and discoloured crown
- crown
- anterior teeth with intact marginal ridges and discoloured crown
- anterior teeth with marginal ridges destroyed (+ core build up)
- post crown
- anterior teeth with marginal ridges destroyed
12
Q
What is a post/core?
A
- restoration gaining intra-radicular support for definitive restoration
- core
- provides retention for crown/bridge
- prosthesis cemented to core
- post
- placed into canal
- retains core
- bonded to remaining tooth structure
- do not strengthen teeth
- preparation for post weakens tooth
13
Q
What are the guidelines for post placement?
A
- tooth type
- incisors and canines
- post necessary if sufficient coronal dentine present - mandibular incisors
- avoid due to thin, tapering, narrow mesiodistal roots - premolars
- small pulp chambers and tapering roots
- thin in mesiodistal cross-section and proximal investigations
- post to be placed in widest root canal
- avoid placement in curved canals to avoid perforations - molars
- avoid
- commonly fail
- easy to get wrong angulation
- increased perforation risk
- if no other option, use longest, straightest canal
- incisors and canines
- root filling length
- 4-5mm apically
- must maintain apical seal
- post width
- no more than 1/3 root width at narrowest point
- 1mm remaining circumferential coronal dentine
- alveolar boen support
- sufficient
- at least half post length into root
- 1:1 post length-crown length ratio
- ferrule
- at least 1.5mm height and width of remaining coronal dentine
14
Q
What would be considered an ideal post?
A
- parallel sided
- avoids wedging
- more retentive than tapered
- decreases fracture risk
- non-threaded
- passive
- smooth surface incorporates less stress to remaining tooth
- cement retained
- less retentive than threaded
- cement is a buffer between masticatory forces and post/tooth
- usually glass ionomer cement
15
Q
What are the different ways to classify posts?
A
- manufacture
- pre-formed/pre-fabricated
- custom made
- material
- cast metal
- steel
- zirconia
- carbon/glass fibre
- shape
- parallel sided or tapered
16
Q
What materials can be used to make posts?
A
- metal
- poor aesthetics
- root fracture
- corrosion
- nickel sensitivity
- radiopaque on radiographs
- cast gold
- stainless steel
- brass
- titanium
- ceramics
- high flexural strength and fracture toughness
- favourable aesthetics
- difficult retrievability
- root fracture common
- alumina
- zirconia
- fibre
- flexible, similar properties to dentine
- aesthetic
- retrievable
- bond to dentine with DBAs
- radiolucent on radiographs
- glass
- quartz
- carbon
17
Q
What are the most common materials for posts?
A
- metal
- glass fibre
18
Q
What are pre-fabricated posts?
A
- pre-made posts
- only 1 visit required
- no impressions or lab visit
- chairside core buildup
- post and core different materials
- immediate preparation of core
19
Q
What are custom posts?
A
- cast from direct pattern fabricated in patients mouth
- duralay
- indirect pattern can be fabricated in lab
- impression of post hole
- wax up of post and core
- most common method
- unified post and core
- 2 visits required
- impression and fit
- temporisation between visits
- risk of contamination
- impression and fit
- Type IV heat hardened gold
20
Q
What are the restoration options for posterior teeth after RCT?
A
- gold standard in cusp protection restoration
- minimal standard prep
- 2mm reduction over cusp
21
Q
What is a core build up?
A
- internal part of tooth is built up with restorative material
- replaces lost tooth tissue
- core prepared
- provides retention and resistance for definitive restorations
22
Q
What materials can be used for core-build up?
A
- composite
- most common
- good aesthetics
- bonds to tooth structure
- technique sensitive, moisture control required
- used with fibre posts
- Paracore and Corecem
- amalgam
- avoided as retention is poor
- poor aesthetic
- core not prepared straight away, 24 hours to set
- avoid pinned amalgams
- glass ionomer
- not used as absorbs water
- core expands in size
- SDR
- bulk fill
- colour not aesthetic
- biodentine
23
Q
What is Nayyar core?
A
- root treatment removed from canals
- 2-3mm coronal GP
- restorative material packed into root canals then tooth built up
- provides retention
- traditionally amalgam
- now more commonly amalgam
- challenging if re-treatment required
24
Q
What is ideal core design?
A
- creation of core as if crown prep on fresh tooth
- 6 degree taper
- length required
- e.g. 2mm clearance for MCC
- short cores do not retain crowns
- results in rocking and rotation
25
What kind of provisional restorations can be placed?
- provisional post core crown
- temp-bond
- immediate denture
- dressing
- poor aesthetics
- prevents leakage
- Essex retainer
26
What is involved in GP removal?
- placement oof dental dam
- softening of GP
- using solvent or heat
- Gates-Glidden
- minimum size 3 (0.9mm)
- straight part of canal only
- use working length and rubber stopper
- creates path of least resistance for post
- leave 3-5mm GP in apical third
- check GP plug remains
27
What is Para Post XP?
- kit for indirect posts and packing techniques
- components
- provisional post
- temporary restoration
- para post drill
- impression post
- sent to lab
28
What does post prep involve?
- preparation of post space
- placement and adjustment of impression post
- impression taken
29
What is an anti-rotation notch/groove?
- small vertical groove in canal
- located in bulkiest area of the root
- requires sufficient coronal structure
30
What does try in of post and core involve?
- check post space for remaining temporary bond
- irrigate with chlorhexidine 0.2%
- dry with paper points
- ensure fits around prep
- check for 2mm occlusal clearance
31
What does fit of a post and core involve?
- protect airway and practice insertion
- once cement is added only one shot at insertion
- do not fill post space with cement
- may prevent proper seating
- use firm apical pressure
- remove excess cement
- take impressions
- fit crown
- place provisional acrylic crown
32
What problems can occur with post crowns?
- perforation
- repair internally or externally (periradicular surgery)
- extraction
- core fracture
- root fracture or crack
- indicated by repeated debonding
- flexion on biting debonds cement
- vertical most common on lateral and central incisors
- post fracture
- post may remain in tooth
- must be removed
- endo-ultrasonic
- masseran kit
- eggler
- moskito forceps (screw retained)
33
What are the possible reasons for post failure?
- mostly restorative (60%)
- some periodontal (32%)
- some endodontic (8%)
