Restorative Flashcards
extrinsic causes of tooth discolouration
- smoking
- tannins - tea, coffee, red wine, guinness
- chromogenic bacteria
- chlorhexidine
- iron supplements
intrinsic causes of tooth discolouration
- fluorosis
- tetracycline
- non-vitality - blood products
- physiological age changes
- dental materials - amalgam, GP etc
- porphyria - red primary teeth
- cystic fibrosis - grey teeth
- thalassemia, sickle cell anaemia - blue, green or brown
- hyperbilirubinaemia - green
first method of whitening for extrinsic staining should always be
- HPT
- no clue what this potentially hygiene phase therapy??
types of tooth bleeching
- external vital bleeching
- internal non-vital bleeching
- can be used together in non-vital teeth
summary of vital external bleeching and how discolouration formed
- discolouration caused by formation of chemically stable chromogenic products within the tooth substance
- these are long chain organic molecules
- bleaching oxidises these compounds which leads to smaller molecules which are often not pigmented
- oxidation can cause ionc change in metallic molecules leading to lighter colour
vital external bleeching
active agent
- hydrogen peroxide h2O2 is the active agent
- forms an acidic solution in water
- free radical per hydroxyl HO2 formed which is the active oxidising agent
- used also to bleach hair and as disinfectant
constituents of bleaching gel
- carbamide peroxide
- carbopol
- urea
- surfactant
- potassium nitrate
- calcium phosphate
- fluoride
constituents of bleaching gel
carbamide peroxide
- active ingredient
- breaks down to produce hydrogen peroxide and urea
- 10% carbamide peroxide makes 3.6% H2O2 and 6.4% urea
- urea increases pH
constituents of bleaching gel
carbopol
- thickening agent
- slows the release of oxygen
- increases the viscosity of the gel - stays on teeth and in tray
- slows diffusion into enamel
constituents of bleaching gel
urea and surfactant
- urea - raises pH and stabilises hydrogen peroxide
- surfactant - allows the gel to wet the tooth surface
constituents of bleaching gel
potassium nitrate, calcium phosphate and fluoride
- potassium nitrate, calcium phosphate - tooth desensitising agents
- fluoride - prevents erosion and desensitising effect
external vital bleaching
factors affecting bleaching
- time - more time increases effect
- cleanliness of tooth surface - cleaner = better
- conc of solution - higher conc = more and quicker effect
- temp - higher = quicker effect
external vital bleaching
before you start
- check pt is dentally fit - leakage around carious margins will lead to pulpal damage
- take an initial shade and record in notes
external vital bleaching
warnings for pt
- sensitivity
- relapse
- restoration colour
- allergy
- might not work
- compliance with regime
external vital bleaching
two types
- chairside/in-office
- home
- advantages and disadvantages to both
external vital bleaching
in office bleaching advantages and disadvantages
- advantages
* controlled by dentist
* can use heat/light
* quick results - disadvantages
* time for dentist
* can be uncomfortable
* results wear off quicker
* expensive
in office bleaching technique
- thorough cleaning of tooth
- ideally rubber dam
- at least gingival mask
- apply bleaching gel to tooth
- apply heat/light
- wash/dry/repeat
- takes 30mins to an hour
external vital bleaching
heat/light/laser
- often used with in-office bleaching
- mainly a marketing technique
- no evidence of better bleaching
- light and laser just heat sources
- often good initial result - due to dehydration - wears off quickly
maximum percentage for home vital bleaching
- 16.7% carbamide peroxide equates to 6% hydrogen peroxide
- the maximum strength of solution
- anything stronger than this is illegal
external vital bleaching
home vital bleaching summary
- 10-15% carbamide peroxide gel
- pt uses solution at home
- custom made tray
- bleaches slowly over several weeks
- easy for dentist and pt
home vital bleaching technique
- alginate impressions of teeth - 0.5mm soft acrylic, vacuum formed splint made
- should stop 1mm short of gingival margin and buccal spacer to allow for placement of gel
- in surgery - full mouth clean/polish & fit trays and instruction in use
- at home - load tay 1mm dot buccally on each tooth
- wear in place for at least 2 hours, prefrably overnight
- written instructions given and review at 1 weeks
home vital bleaching
variable results
- most pts see result in 2-3days
- normally reached maximum by 3-4weeks
- if no change in 2 weeks it is not going to work
external vital bleaching
when to bleach
- if age related darkening - teeth with yellow/orange discolouration respond better than those with bluish/grey
- mild fluorosis
- post smoking cessation - dont bleach smokers waste of time
external bleaching problems
- sensitivity
- wears off
- cytotoxicity - high conc H2O2
- gingival irritation - related to conc
- tooth damage
- damage to restorations - teeth bleach comp doesnt
- problems with bonding to tooth
external bleaching problems
sensitivity
- common 60% +
- worse initially
- resolves over 2-3 days post bleaching
- predictors - pre-existing sensitivity, high conc, bleaching method, gingival recession
bleaching problems
wears off
- oxidised chromogens gradually reduce with time
- retreatment 1 - 3 years
- varies
external bleaching problems
bonding& how long to delay rest tx
- residual oxygen from peroxide remains within enamel structure initially
- gradually dissipates over a short time
- delay restorative procedures for at least 24h post bleaching
- better to delay for a week
why you should never use chlorine dioxide for external bleaching
- ph of 3 will soften tooth surface
- makes teeth more prone to re-staining
- teeth develop a rough surface and become extremely sensitive
What causes teeth to require internal non vital bleaching
Dead pulp causing bleeding into dentine
Blood products diffuse and darken
Causes grey discolouration
Internal non vital bleaching indications and contraindications
Indications - non vital tooth, adequate RCT, no apical path
Contraindications - heavily restored tooth (better with crown or veneer), staining due to amalgam
Internal non vital bleaching
Advantages
Easy
Conservative
Patient satisfaction
Internal non vital bleaching
Risks
External cervical resorption due to diffusion of H2O2 through dentine and into periodontal tissues
Increased risk from high conc H2O2 and heat
Trauma important consideration
Internal non vital bleaching
Technique access
- record shade, prophylaxis and rubber dam
- Remove filling from access cavity and remove GP from pulp chamber to 1mm below amelo-cemental junction
- Place RMGIC over GP to seal canal - prevents root resorption
Internal non vital bleaching
Technique after access
- Remove any very dark dentine
- Etch internal surface with 37% phosphoric acid
- Place 10% carbamide peroxide gel in cavity and cotton wool over this
- Seal with GIC
- Repeat procedure at weekly intervals and until required shade achieved or no change
How many visits does Internal non vital bleaching normally take
Normally takes 3-4 visits
If no change after 4 visits it is not going to work and consider crown/veneer/composite build up
Internal non vital bleaching
Technique once final shade obtained
Restore the palatal cavity
1. Place white GP or similar into pulp chamber
2. Restore with light shade of composite
Internal non vital bleaching
Reasons for retreatment
Will gradually darken again
Retreatment every 4-5 years but this is variable
What is combination bleaching and technique summary
- inside-outside bleaching
- remove GP and cover with RMGIC
- make bleaching tray (palatal not buccal reservoir)
- bleach placed in access cavity and in tray
- replaced frequently over about a week
-tricky for patient must wear tray whole time
Microabrasion function/summary
Removes discolouration limited to the outer layers of enamel
Combination of erosion (acid) and abrasion (pumice)
Micro-abrasion indications
- fluorosis
- post orthodontic demineralisation
- demineralisation with staining
- prior to veneering if staining is present
Micro-abrasion
Technique
- Clean teeth thoroughly
2 rubber dam as seal very important - Mix 18% HCl and pumice and apply to teeth
- Gently rub with a prophy cup 5 seconds per tooth
- Wash and repeat up to 10X
- Remove rubber dam
- Polish teeth with fluoride prophy paste
- Apply fluoride gel or varnish
Micro-abrasion
Review / repeat treatment
Review after one month
Can be repeated
Too much repetition can lead to yellowing of the tooth as dentine begins to show through
Too much can also lead to permanent sensitivity
Micro-abrasion
Advantages and disadvantages
Advantages
- quick, easy
- no long term problems such as pulp all damage or caries
Disadvantages
- acid
- sensitivity
- only works for superficial staining
- works much better for brown staining than white marks
Micro-abrasion
Option rather than using HCl
Can use 37% phosphoric acid rather than HCl
- will remove only 10microns compared to 100 microns with HCl
- etch first for longer than 30s prior to using pumice
- not as effective but this acid is readily available to GDP
Tooth whitening
Resin infiltration summary
-surface layer not removed
- infiltrate the white area with resin
- changes the refractive index of the white area
- masks it and makes it look like the surrounding enamel
- used for tx of white spot lesions
- hydrophilic resin impregnation of the porous enamel surface in white area
Resin infiltration immediate result and aesthetic durability
Appears to demonstrate an immediate masking effect
- aesthetic result durability uncertain requires further studies
- could be due to potential staining and ageing of the low viscosity resins used
Legislation for tooth whitening and differences between UK and America
- the cosmetic products regulations 2012
- in UK tooth bleaching products considered cosmetic
- in USA they are a medical device
Medico-legal issues for tooth whitening
Clinical examination to assess
- free of dental pathology
- medical contraindications
Medical contraindications to tooth whitening
- glucose-6-phosphate dehydrogenase deficiency
- acatalasemia
- neither group can metabolise hydrogen peroxide
Percentage of tooth whitening products which are illegal
- products which contain more than 6% hydrogen peroxide
- or any associated products which release greater than 6% hydrogen peroxide
- cannot be supplied or administered for cosmetic purposes
Age limits for hydrogen peroxide and percentages on the market
- products containing between 0.1% and 6% hydrogen peroxide cannot be used on under 18s (except if intended wholly to prevent disease)
- ^ these products should not be made directly available to consumer other than tx from dentist or dental hygienist etc under a dentists prescription
- breaches of regulations a criminal offence
- enforced through trading standards
- 0.1% products such as mouth rinse, toothpaste and tooth whitening or bleaching products are safe and continue to be available on the market
Medico-legal issues with tooth whitening summary
- whitening products only sold by dental practitioners
- first cycle of tx must be supervised
- conc higher than 6% hydrogen peroxide prohibited unless wholly for the purpose of prevention of disease
- criminal offence to breach these guidelines
Prosecution of tooth whitening bleaching product breach
- dentists supplying bleaching products in excess of 6% will be prosecuted by trading standards
- if dental professional found to do this they will face fitness to practice proceedings
- non registrants providing tooth whitening will be prosecuted by GDC under dentists act 1984 for illegal practice of dentistry
4 main materials used for indirect restorations
- ceromer - inlays/onlays
- ceramic
- gold - type IV post cores and III crowns
- metal ceramic
what is used to make index for indirect restoration fabrication
- poly-vinyl siloxane PVS
- made before any tooth preparation
guidelines for preparation of inlays and onlays
- ensure no cavosurface margins pass through areas of occlusal contact and are clear of contact with adjacent tooth and accessible for cleaning
- ensure a butt joint is present on all cavosurface margins
- smooth occlusal cavosurface margins and line angles
- ensure outline form is smooth and rounded
- all internal line angles should also be rounded
- ensure no undercuts and all axial walls are minimally divergent
when to take definitive impression for inlay/onlay
- after provisional restoration has been constructed
- on day of tooth preparation
- for valid clinical reasons you may not always intend to record the definitive impression on day of tooth prep
fixed prosthdontics definition
- area of prosthodontics focused on permanently attached (fixed) dental prosthesis
- also referred to as indirect restorations
types of indirect restoration
- veneers
- inlays and onlays
- crowns
- post and cores
- bridgework
fixed prosthodontics
special investigation/additional info
- sensibility testing
- radiographs
- study models
- facebow
- diagnostic wax up
- diet diary
- plaque and gingivitis indices
- clinical photographs
what part of tx plan is fixed prosthodontics
reconstructive
why not use inlays/onlays
- active caries and periodontal disease
- time - tooth preparation and labatory fabrication required
- cost
principles of crown prep
- preservation of tooth structure
- retention and resistance
- structural durability
- marginal integrity
- preservation of the periodontium
- aesthetic considerations
principles of crown prep
1. preservation of tooth structure
- whenever possible preserve sound tooth structure
- this is to avoid unnecessary weakening of tooth structure and damage to pulp
- must balance against criteria for retention/resistance and structural durability
principles of crown prep
under/over prep results in
- under prep - poor aesthetics, over built crown with periodontal and occlusal consequences, restorations with insufficient thickness
- over prep - pulp and tooth strength compromised
principles of crown prep
retention and resistence
- retention - prevents removal of restoration along path of insertion or long axis of tooth prep
- resistence - prevents dislodgement of restoration under occlusal forces
- retention is improved by limiting the number of paths of insertion
- taper - 6-10degrees is ideal inclination of opposing walls
- extra means of retention - grooves, slots
principles of crown prep
structural durability
- restoration must contain a bulk of material that is adequate to withstand the forces of occlusion
- achieved through:
- occlusal reduction
- functional cusp bevel
- axial reduction
principles of crown prep
marginal integrity
- correct finish line configurations for type of material
- knide edge
- bevel
- chamfer
- shoulder
- bevelled shoulder
principles of crown prep
preservation of the periodontium
- margins of the restoration should be
1. smooth and fully exposed to a cleansing action
2. placed where a dentist can finish them and the patent can clean them
3. placed supra-gingival or at gingival margin whenever possible - placement of the margins subgingival may be required
principles of crown prep
aesthetic considerations
- which material provides best aesthetics - will the restoration be visible
- has the least destructive prep
- is least destructive to opposing teeth
- best suited to bruxists
why replace teeth with bridgework
- aesthetics
- occlusal stability - prevent tilting and overeruption of adjacent and opposing teeth
- for function - mastication, speech
- periodontal splinting
- patient preference
why not replace teeth with bridgework
- damage to tooth and pulp
- secondary caries
- effect on the periodontium
- cost
- failures
bridge designs
- cantilever - one adjacent tooth crowned to support bridge
- fixed-fixed - conventional with rigid connectors
- adhesive/resin-bonded/maryland - wings on either side of the pontic that are attached to your abutment teeth by an adhesive
- conventional - crown teeth either side of bridge
- hybrid
- spring cantilever - posterior tooth used as retainer for anterior tooth pontic
- implant supported
fixed prosthdontics what to communicate with pts
- invasiveness/reversibility
- longevity and success rates (evidence based)
- possible complications
- time involved
- costs
- alternative options
anterior crown prep considerations
- conservation of healthy tooth tissue - avoid weakening structures or compromising pulp
- axial and occlusal reduction should provide sufficient space for material
- reductions should also provide resistence form - axial symmetry, optimal taper
- margin appropriate for material used and for relationship with periodontal tissues to allow optimal hygiene
- prep surface smooth whit no sharp line or point angles
anterior crown prep
metal ceramic crown prep dimensions
- 1.5-2.5mm incisal reduction to accomodate porcelain and metal
- 1.5mm buccal shoulder required and in aesthetic areas may be placed approx 1mm into gingival sulcus
- non aesthetic margins for metal should be chamfered 0.5mm and placed supra-gingivally
stages in anterior crown preparation
- incisal reduction - can use depth cuts as guide
- proximal separation - separation bur along long axis of tooth
- buccal reduction (2. and 3. interchangable)
- palatal or lingual reduction
- shoulder and chamfer finish - with dam off
- occlusion check/adjustment
- polishing the preparation
type of margin for metal ceramic crowns
- shoulder buccally
- chamfer lingually - as margin made only from metal
porcelain veneers summary
- used to imporve anterior aesthetics
- typically thin laboratory made
- have a finite life span - consider when tx planning
- usually necessary to remove healthy tooth tissue - consider alternative of direct composite veneers
- hand made usually better aesthetics - ceramicist build layers of diff porcelian to give colour depth and translucency
- CAD-CAM normally milled from block of porcelain - colour variations added post milling
what can be used to ensure subgingival margin of veneer
- gingival retraction cord
- once dam removed
- to assist with placing the margin subgingivally
anterior veneer impression
- take putty indices BEFORE tooth preparation
- a sectional index tray used
- if take 2 - one index can be used to make provisional veneer and other as a reduction template
anterior veneer prep stages ensuring incisal bevel preparation
- incisal edge enamel reduced by 0.75-1.5mm to produce incisal bevel finish
- labial enamel reduced by approx 0.5mm - depth cuts can help guage amount of reduction - ensure labial face has 3D curve and not a flat cut (preserve curvature)
- chamfer finish line prepared cervically at or just above gingival margin
- proximal chamfer extended towards contact area
- preparation finished and smoothed with red and yellow band high speed diamond burs or silicone disc
posterior crown prep considerations
- conservation of healthy tooth tissue - avoid weakening structures or compromising pulp
- axial and occlusal reduction should provide sufficient space for material
- reductions should also provide resistence form - axial symmetry, optimal taper
- margin appropriate for material used and for relationship with periodontal tissues to allow optimal hygiene
- prep surface smooth whit no sharp line or point angles
metal ceramic crown prep on posterior teeth dimensions
- approx 2.5mm occlusal reduction to accomodate porcelain and metal (1-1.5mm if metal only)
- 1.5mm buccal shoulder required in aesthetic areas - may be placed 1mm into gingival sulcus
- non aesthetic margins should be chamfered and placed supra-gingivally
- 5-7 degree taper recommended
- ensure some occlusal anatomy morphology retained to increase resistance to rotational forces
all ceramic crown prep on posterior teeth dimensions
- approx 2.5mm occlusal reduction necessary to accomodate zirconia framework and porcelain veneer - less may be required for lithium disilicate
- 1.5-2mm buccal shoulder or long chamfer circumferentially - approx 1mm into gingival sulcus
- non aesthetic margins should be chamfered and placed supra-gingivally unless additional prep height required
- 5-7 degree taper recommended
posterior crown preparation stages
- occlusal reduction - using short tapered fissure bur can make depth cuts + functional cusp bevel
- proximal separation - fine pointed diamond bur
- buccal reduction
- palatal or lingual reduction - blend buccal and lingual reductions
- shoulder/chamfer finish
- occlusion check/adjustment
- polishing the prep
reasons to place posterior metal ceramic crown
- secondary caries
- cuspal fracture - is tooth restorable?
- need to make clinical decision on whether tooth can be restored directly, by inlay/onlay, or requires full coverage crown
bur type for shoulder margin
- long tapered diamond bur
- with flat end
- on high speed
most common means of inlay construction
- chairside in surgery with a CAD/CAM system - constructed inlay bonded at same visit
- in a lab from an impression taken in surgery - inlay made from model directly or via lab CAD/CAM system - bonded at subsequent visit
inlay/onlay undercuts
- NO UNDERCUTS if restoration is to be fitted
- undercus can be blocked out using GI, flowable composite, or removed
- only dentine may be blocked out
- enamel undercuts must be removed as blocking out materials will not support unsupported enamel and must not reach cavo-surface margin as will compromised bonding of inlay to enamel
principles of cavity prep
- identify and remove carious enamel
- remove enamel to identify maximal extent at ADJ and smooth enamel margins
- remove peripheral caries in dentine - from ADJ first then circumferentially deeper
- only then remove deep caries over pulp
- outline form modification - cavo surface margin, enamel finishing, requirements of rest. material
- internal design modification - internal line and point angles smoothes and rounded, requirements of res. material
how to take impression of inlay/onlay prep
- inject sufficient material to cover entire prep
- material used in PCS was poly-vinyl siloxane (addition silicone)
- seat a tray filled with same material over the arch
- allow setting without moving the tray
- ensure impression of opposing arch also sent to lab
stages of chairside CAD/CAM inlay/onlay
- preparation isolated and coated with a layer of titanium dioxide - as optical impression in 3D can only be recorded in monochrome
- silicone interdental record of the morphology of opposing teeth is then placed on prep and also coated
- optical 3D images processed by unit
- inlay then milled from a block of leucite reinforced porcelain or lithium disilicate
- takes approx 14 mins to mill
- restoration bonded with self adhesive resin cement
tx of lower incisor wear
- impressions to send to lab
- lab wax up incisors to recreate morphology prior to wear on study cast
- make a template from the wax up to assist with clinical direct composite build up
- rebuild lower incisors using template
* build up lingual surfaces and incisal edges first
* proximal and labial surfaces may be reconstructed next
* continued use of wedges and matrices
provisionals restore what characteristics of tooth prep
- compromised aesthetics in smile line
- degrades tooth function: occlusal reduction which destabilises occlusion
- occlusal and interproximal reduction can render a tooth sensitive - exposed dentine
- compromise coronal seal of RCTd teeth in some cases
- provisional extra-coronal restorations should restore these characteristics
extra-coronal provisional restorations should
- have good marginal fit
- be well contoured - no overhangs
- cleansable and maintainable by pt - prevent plaque build up and caries - maintain gingival health and contour
- establish and/or maintain dental aesthetics - mimic original tooth or definitive restoration
- prevent sensitivity
- prevent microleakage - preserve tooth vitality
extra-coronal provisional restorations - poorly fitted/contoured
- patient unable to clean
- can result in caries
- gingival inflammation - poor moisture control, gingival overgrowth
extra-coronal provisional restorations
ideal material characteristics
- non irritant to pulp/periodontal tissues
- low temp rise during setting
- dimensionally stable
- adequate working and setting tume
- adequate strength and wear resistance
- good aesthetics
types of extra-coronal provisional restorations
- custom formed - bespoke to individual situations, preferable, can be technically demanding
- preformed - standard shapes and sizes - adjust to fit chairside
custom resin provisional crowns
materials
- chemically cured bis-acrylic composite resin
- examples: protemp plus, integrity temp-grip
- customisabe - fits tooth prep internally and reproduces contact points and occlusion externally
- protemp most commonly used
custom resin provisional crowns
make before…
- impressions for definitive restoration are taken
- helps check that tooth prep is satisfactory
- check for undercuts
- sufficient reduction
custom resin provisional crowns
method
- sectional impression
- prepare tooth for chosen restoration
- syringe bis-acrylic composite resin material onto bracket table/mixing pad to ensure its mixed and monitor setting
- syringe material into sectional impression of tooth that has been prepared
- relocate impression in the mouth - ensure fully seated
- remove before complete polymerisation
- remove flash and ledges - hig speed and/or polishing discs
- confirm tooth preparation - svensen gauge
- check marginal fit and occlusion in situ - adjust if required
- check aesthetics
- cement provisional restoration
custom resin provisional crowns
svensen gauge function
- used to check degree of preparation
- ruler at bottom
- put provisional between pincers and will show what thickness the provisional is
custom resin provisional crowns
impression/materials/alternative
- sectional impression - full arch impression unnecessary
- materials:
- addition cured silicone putty - can be reused
- alginate - cannot be reused
- softened modelling wax - cannot be reused
- alternative: custom vacuum formed plastic mould - made on study model and/or diagnostic max-up in advance
extra-coronal provisional restorations
establishing occlusion and aesthetics if changing
- loss of original tooth form (eg wear cases) - temp re-establishes tooth shape and can pilot occlusion and aesthetics using provisional restorations
- guidance (anterior/incisal) produce using diagnostic wax up on articulated study models (facebow refistration required)
- once guidance and aesthetics satisfactory duplicate waxed-up cast and construct vacuum-formed mould/stent/template and next visit prepare teeth and use stent to produce provisional restoration to new occlusion/aesthetics
extra-coronal provisional restorations
patient trial
- wear until happy with - form/function
- adjust/alter - trim with bur, addition of composite, reassess
extra-coronal provisional restorations
toothwear case summary
- obtain mounted casts
- lab: produces diagnostic max up and duplicates cast then constructs vacuum stent over duplicate cast
- carry out tooth prep if required
- use stent and provisional material to produce provisional restorations
- patient wears provisionals for trial period
- reassess: aesthetics, occlusion
- if satisfactory procees to definitive restorations
extra-coronal provisional restorations
establishing gingival contours
- use provisional restorations to achieve satisfactory emergence profile for definitive restorations
- emergence profile - contour of tooth/restoration as it emerges from the gingivae
preformed provisional crowns
variations
- tooth coloured: polycarbonate (directa) or clear-plastic crown froms filled with composite
- metal: aluminium or stainless steel
- different shapes/morphology and sizes
preformed provisional crowns
positives and negatives
- : useful for situations where no impression taken prior to tooth prep or damage eg trauma cases
- : unlikely to fit accurately and large bank of crowns needed to accomodate variation between pts - costly
preformed provisional crowns
method
- select shell slightly larger than prep
- trim back until correct prep dimension, seats fully over pre and not bedding into gingivae
- fill shell with trim/protemp
- seat over tooth - wipe away excess - microbrush good
- allow polymerisation
- remove and check fit
- trim/tidy if necessary
- cement using temp luting cement eg tempbond
- cut off tag
clear plastic provisionals method
- select and trim until fit
- pierce hole at cusp tip/canine tip/incisal angle - air escapes so no bubbles
- fill with bis-acrylic composite resin
- seat over tooth
- allow setting
- remove from tooth and remove plastic crown form
- check margins and occlusion - adjust if necessary
- cement with temp cement
metal preformed crowns overview
- used for posterior teeth
- materials: aluminium, stainless steel
- remove any ledges and sharp margins - reduce soft tissue trauma
- difficult to adjust - use crimping device to help mould margins
provisional crowns if replacing an old crown
- can use/modify original crown for temporary - may need partially sectioned/relined
- removal using WAMkey, saferelax, sliding hammer
preformed malleable composite crowns overview
- eg protemp crown temporisation material
- soft and easily mouldable to tooth preparation
- moulded over tooth to desired shape
- partially light cured - 2/3 seconds (otherwise difficult to remove)
- remove then completely cure outside mouth
- check fit/adjust if necessary
- cement
provisional replacement of missing teeth options
- conventional bridgework temporisation - similar to custom-formed provisional crowns - diagnostic wax up of replacement tooth
- acrylic RPD
- essix retainer with pontic
- edentulous space and only provisional crowns on prepared teeth
extra-coronal provisional restorations pt advice
- maintain good OH: brush 2-3 x daily, interdental cleaning 1-2 x daily
- caution with floss - may pull out provisional restoration
- gingival inflammation increases GCF/bleeding so poor moisture control for definitive restorations
types of indirect restorations
- crowns
- posts and cores
- bridgework
- inlays and onlays
- veneers
indirect restoration special incestigations
- radiographs: caries, perio, periapical, previous RCT
- sensibility testing
- mounted study models: semi or fully adjustable articulator
- diagnostic wax up: aesthetics, occlusion, achievability
chariside indirect restorations
- CAD-CAM
- restorations milled from block of ceramic
- quick
- no temporary needed
- accuracy??
what are inlays
- intra-coronal restorations made in lab
- like a filling made outside the mouth
inlays types and overall advantages/disadvantages
- gold
- composite
- porcelain
- A: superior materials and margins (vs direct restoration) and wont deteriorate over time
- D: time and cost
inlays uses
- occlusal cavities
- occlusal/interproximal cavities
- replace failed direct restorations
- minor bridge retainers - no longer recommended
inlays indications
- premolars or molars
- occlusal restorations
- mesio-occlusal or disto-occlusal restoration
- MOD if kepy narrow - if not consider onlay
- low caries rate
inlays temporisation and impression summary
- make temporary restoration
- take impressions and occlusal records - send to lab for restoration fabrication (2 weeks typically)
- fit temporary restoration
- alternative: direct temporary materials - ZOE, GI, clip
inlay cementation summary
- ceramic inlays: weak when not cemented so dont check occlusion as may fracture; uses adhesive systems - nexus, ABC, relyx unicem
- nexus is dual cure composite luting agent
- gold inlays: aquacem; panavia; RMGI
inlay/onlay communication with lab (prescription)
- pour impressions
- mount casts on articulator: waxbite; occlusal record; facebow
- construct restoration: tooth (FDI); material; thickness; shade; characteristics
what are onlays and types of onlay
- extra-coronal restorations made in lab
- like inlays but with cuspal coverage
- height of cusps need to be reduced during preparation
- types: gold; composite; procelain
onlay prep summary for porcelain
- 1.5mm occlusal reduction (non working cusp)
- 2mm reduction (working cusp)
- proximal box if required 1mm
- 1mm shoulder or chamfer margin
- tapered walls - no undercuts
- butt joint cavosurface margins - no bevels
- flat pulpal floor
- rounded internal line angles
- margins clear of occlusal contact points
onlay prep summary for gold
- 0.5mm occlusal reduction (non working cusp)
- 1mm occlusal reduction (working cusp)
- 0.5mm chamfer margin
- proximal box if required 1mm
- 4-6degree tapered walls - no undercuts
- 12-20 degree bevel upper 1/3 of isthmus wall
- margins clear of occlusal contact points
- flat pulpal floor
onlay indications
- sufficeint occlusal tooth substance loss - buccal and/or lingual cusps remaining
- remaining tooth substance weakened - caries, pre-existing large restoration (MODs with wide isthmuses)
- cast metal onlays preferable to amalgam when higher strength needed and significant tooth recontouring required
onlay uses
- toothwear cases - increase OVD
- fractured cusps
- restoration of root treated teeth
- replace failed direct restorations
- minor bridge retainers - not recommended
- less destructive alternative to crowns
inlay and onlay 1st appointment
- LA if no RCT
- make reduction template and impression for temporary
- tooth preparation
- make temporary
- impression, bite registration and record shade
- cement temporary
inlay and onlay 2nd appointment
- remove temp
- isolate, clean and dry prepared tooth
- try in, assess fit, adaptation, occlusion etc
- if happy to cement - cement and minor occlusal adjustments if needed
- if not happy to cement - address problems
inlays/onlays alternatives
- large direct restorations: amalgam, composite, GI
- crown: 3/4 crown in gold, full crown - GSC, MCC, PJC
- extraction
what are veneers
- also called porcelain laminate venner PLV or laminate veneer
- lamiinate veneer is a thin layer of cast ceramic that is bonded to labial or palatal surface of a tooth with resin
- types: ceramic; composite; gold
veneer indications
- improve aesthetics
- change teeth shape and/or contour
- correct peg-shaped laterals
- reduce or close proximal spaces and diastemas
- align labial surfaces of instanding teeth
- correct discolouration/enamel defects
enamel defects/discolouration causes
- non-vital teeth
- ageing
- trauma
- fluorosis
- hypoplasia or hypomineralisation
- amelogenesis imprefecta
- erosion and abrasion
- extrinsic: staining not amendable to bleaching
veneer contraindications
- poor OH
- high caries rate - interproximal caries and/or unsound restorations
- gingival recession
- root exposure
- high lip lines
- if extensive prep needed
- labially positions, severely rotated and overlapping teeth
- extensive TSL/insufficient bonding area
- heavy occlusal contacts
- severe discolouration
veneer preparation types
- feathered incisal edge
- incisal bevel
- intra-enamel (window)
- overlapped incisal edge
veneer prep dimensions
- 0.3mm cervical reduction - slight chamfer margin within enamel which is supragingival or slightly subgingival
- 0.5mm midfacial reduction within enamel
- 1-1.5mm incisal reduction
veneer temporary alternative
- may not need temp
- alternative - spot bonded composite
- no etch
- small spot of primer and adhesice
- directly apply composite
veneer alternatives
- no tx
- micro-abrasion
- penetrative resin restorations eg ICON
- direct composite restorations
- crowns
trauma management outcome predictors
- severity of injury sustained
- stage of root development
- timing of treatment
trauma management outcome predictors
severity of injury sustained
- can use risk calculator: IADT dental trauma guide
- prognosis for teeth with traumatic dental injuries
- www.dentaltraumaguide.org
crown # relative risk of complications closed apex
- ED#: 5% risk of pulp necrosis and 1/3% risk of pulp canal obliteration at 10 years
- EDP#: 20% risk of pulp canal obliteration at 10 years
pulp canal obliteration
- hard tissue is deposited along the internal walls of the root canal and fills most of the pulp system
- leaving it narrowed and restricted
concussion relative risks of complications closed apex with no crown #
- pulp necrosis: 3.5% at 10 years
- pulp canal obliteration: 10.3% at 10 years
- external root resorption: 8% at 10 years
subluxation relative risk of complications
- pulp necrosis: 12.5% at 10 years
external root resorption: 2.7% at 10 years - bone loss: 0.9% at 10 years
extrusion relative risks of complications
- pulp necrosis: 56.5%
- pulp canal obliteration: 21.7%
- external root resorption: 27%
- bone loss: 17.4%
lateral luxation relative risks of complications
- pulp necrosis: 75%
- pulp canal obliteration: 18.3%
- ankylosis: 1%
- internal root resortion: 3/3%
- external root resorption: 33%
- bone loss: 5.8%
dento alveolar fracture relative risk of complications
- tooth loss: 10% at 10 years
- pulp necrosis: 45%
- pulp canal obliteration: 13%
- ankyolosis: 2%
- internal root resorption: 4%
- external root resorption: 5%
- bone loss: 8%
intrusion relative risk of complications at 10 years
- tooth loss: 29%
- pulp necrosis: 100%
- ankylosis: 38%
- internal root resorption: 5%
- external root resortion: 5%
- bone loss: 63%
avulsed tooth - time and type of storage before replanting
- dry storage no more than 4 minutes
- followed by correct transport medium: milk, saliva or saline
- increased dry storage time increasess risk for lost tooth
- 5-60minutes: 44% loss at 10 years
- 61+ minutes: 70% loss at 10 years
trauma management aims
open vs closed apex
- open apex: maintain pulp vitality; preservation or blood supply; aim for regerneration
- closed apex: maintain pulp vitality; preservation of blood supply; prevent ingress of or eliminate bacteria and toxins
trauma management
timings of tx
- acute <3 hours
- subacture 3-24 hours
- delayed >24 hours
- decision made based on pt discomfort, risk of infection, rate of complications
recommended trauma management tx timing protocol
- avulsion: immediate re-implantation and acute tx
- alveolar fracture: acute
- extrusion/lateral luxation: acute or subacture
- root #: acute or subacture
- concussion or subluxation: subacute
- crown or crown-root#: subacture or delayed
trauma management
potential long term complications
- discolouration
- loss of vitality
- inflammatory root resorption: internal, external, replacement
- unfavourable tooth positions
- defects in hard and soft tissues
trauma management
potential long term complications
discolouration overview
- external: accumulation of staining media
- internal: optical and light transmitting properties of enamel and dentine; following trauma may be yellow/pinl/red/grey/black
- diagnosed by visual examination
trauma management
potential long term complications
yellow discolouration
- indicative of canal obliteration
- tertiary dentine reduces light transmission
- monitor for signs/symptoms of loss of vitality
- consider local external bleaching
trauma management
potential long term complications
pink discolourtion
- rupture of BV durig severe trauma - may cause haemorrhage in pulp chamber
- blood components flow into dentinal tubules
- causes discolouration of the surrounding dentin
- initially pink
- cervical root resorption may also present as pink discolouration at cervical margin of crown
trauma management
potential long term complications
brown-grey-black discolouration
- in non-infected truamatised teeth accumulation of haemogrlobin molecule or other haematin molecules causes discolouration
- in non vital teeth hydrogen sulphates produced by bacteria convert iron to dark coloured iron sulphates
trauma management
potential long term complications
reversal of pink discolouration
- if no necrosis discolouration may reverse over time as the pulp revascularises (2-3 months)
- if pulpal necrosis discolouration will worsen over time
trauma management
potential long term complications
pulp necrosis and apical periodontitis
- occurs following trauma if revascularisation fails
- pulp tissue will undergo sterile necrosis - subsequent bacterial infection may then occur
- after 3-4 weeks there will be radiographic indications of pulp necrosis
- can develop to apical periodontitis
- apical radiolucency on radiograph
trauma management
diagnostic indicators of pulp necrosis
- periapical radiolucency
- discolouration of the tooth crown: usually grey/brown
- infection-related external root resorption
- no response to pulp sensitivity test
- tenderness to percussion and palpation in vestibule - develops after an asymptomatic period
- presence of a fistula (sinus tract)
treatment of pulpal necrosis
- primary endodontics
- internal bleaching
- extraction and prosthetic replacement
trauma long term complications
unfavroutable tooth positions overview
- altered tooth position may result following displacement injuries: lucation; intrusion; extrusion; avulsion
- repositioning and splinting withing 24 hours to minimise risk of complications
trauma long term complications
management of unfavourable tooth positions - restorative tx
- addition of composite resin
- removal of tooth tissue
- if significant alterations needed: extra-coronal restorations
trauma long term complications
management of unfavourable tooth positions - orthodontic repositioning
- for late presentation injuries or injuries which have incorrectly repositioned
- increased risks associated with orthodontics: root resorption; loss of vitality
trauma long term complications
unfavourable tooth position as a result of childhood trauma
- occurs if ankylosis/replacement root resorption results from injury
- most likely in severe injuries to PDL: intrusion; avulsion with prolongued EADT
- trauma prior to pre-pubsescent frowth spurt highest risk: continued alveolar growth
trauma long term complications
infraoccluded teeth
- submerge below occlusal plane of adjecent teeth
- mild, moderate or severe
*
trauma long term complications
infraoccluded teeth management
- not amendable to orthodontic repositioning
- best undertaken before >4mm infra-occlusion present
- depends on number of factors: prognosis of teeth; degree of infra-occlusion; wishes of the pt; cooperation of pt; lip line
trauma long term complications
defects in hard and soft tissue overview
- loss of tissue during acute injury: gingival lacerations/abrasions; alveolar #
- developing deficiencies:
- early extraction with significant bone remodelling
- ankylosis: lack of development of alveolar process and gingival margin discrepancy; bone loss during extraction
- endodontic failures
trauma long term complications
management of bone deficiencies in adults
- bone grafting procedures
- orthodontic extrusion therapy: as long as no ankylosis/replacement resorption
trauma long term complications
management of soft tissue deficiencies in adults
- mucogingival surgery
- connective tissue grafting to increase volume of keratinised mucosa
trauma long term complications
management of hard and soft tissue defect sin children
- extraction of teeth = bone loss
- coronectomy: aims for continued bone deposition
- ostegenic distraction: cutting and slowly separating bone, allowing bone healing process to fill gap
- camouflage
trauma long term complications
extraction of teeth
- may be difficult extractions
- potential for further bone loss
- socket preservation
- vertical bone loss more difficult to deal with
- implants challenging
trauma long term complications
how to avoid complications
- correct and timely tx - follow guidelines
- follow up schedule
- onwards referral to specialists at early stages
how long to have splint on for
- intrusion: 4 weeks
- lateral luxation: 4 weeks
- root fracture: 4 weeks
- alveolar fracture: 4 weeks
- extrusion: 2 weeks
- concussion/subluxation: 2 weeks
simple acute traumas
- concussion
- subluxation
- enamel fracture
- enamel dentine fracture
- root fracture: apical 2/3 and no displacement
- avulsion
complex acute traumas
- extrusion
- displaced or cervical 1/3 root fracture
- lateral luxation
- dento-alveolar fracture
- intrusion
- immature apex (paeds)
- onwards referral adult dental trauma service
- injury <5 days old appt same day
- injury >5 days old but no long term complications next available appt
trauma long term complications that may require specialist tx
- inflammatory root resorption: external cervical root resorption, internal inflammatory root resorption, external inflammatory resorption
- altered tooth positions: may require multi-disciplinary care
- root fractures exhibiting developing pathology
- loss of >1 tooth as a result of trauma
guidelines for management of dental trauma
- IADT
- International Association for Dental Traumatology
- 2020 guidelines
