L3 Anterior veneers Flashcards
What is an anterior laminate veneer?
- A thin section of porcelain, composite or gold that hides a disease, damaged or discoloured tooth to provide the illusion of a healthy/undamaged/better coloured tooth
Name indications for veneers.
Intrinsic discolouration:
- Trauma (pulpal haemorrhagic products)
- Hereditary conditions (amelogenesis/dentinogenesis imperfecta)
- Metabolic disease (alkaptonuria)
- Systemic and developmental factors (MIH, tetraycline staining, fluorosis)
Single/multiple tooth issues:
- Tooth malalignment
- Peg lateral
- Spacing
- Microdontia
- Localised trauma, chipped edges
- Discoloured facial restorations
What treatments may be a suitable alternative to veneers?
- Internal/external bleaching
- Direct facial composite placement
- Micro abrasion (e.g. ICON- bleaching and resin infiltrate)
- Orthodontics
- Implant and crown/bridge placement
- Removable partial denture
- Direct bonding composite replacement
What are the contraindications for veneers?
- Poor OH
- High caries risk
- Inability to achieve isolation
- Insufficient enamel to bond
- Parafunctional habits
- Unfavourable occlusion
- Thin gingival biotype (prone to recession)
- Single teeth (pt expectation vs delivery)
What 4 veneer types are there? List from least to most destructive.
- Window
- Feather
- Bevel/butt
- Overlap
Bevel and overlap are the most common type.
What are the advantages and disadvantages of a window preparation veneer?
- Minimal preparation
- Conserves the incisal edge
- Incisal edge enamel weakened
- Margins vulnerable to tooth wear
- Marginal join in the aesthetic zone (visible)
- Incisal luting agent may be difficult to hide
- Challenging to seat
What are the advantages and disadvantages of a feather preparation veneer?
- Incisal edge is maintained
- Interface between veneer and tooth hidden on/just behind incisal edge
- Substantial amount of enamel preserved
- Veneer is liable to be fragile at the incisal edge, incisal edge may fracture
- Subject to peel/sheer forces during protrusion
- Challenging to seat perfectly
What are the advantages and disadvantages of a bevel/butt edge preparation veneer?
- Greater control of incisal aesthetics
- Bigger bulk of porcelain at incisal edge gives greater strength
- Margin not subject to direct shear forces
- Easier to seat
Most common preparation choice.
- More extensive tooth preparation
- Cannot have more than 2mm of unsupported poreclain
What are the advantages and disadvantages of an incisal overlap veneer?
Also called modified butt/taco style
- Positive seating
- Tend to be more successful
- Preparation is more difficult and there is more tooth destruction
- When trying to fit the veneer, the path of insertion requires care and there is a risk of fracture
- Technically more difficult to produce
What are the benefits of bevel/butt and incisal overlap veneer types?
Where should the margin be for a ceramic veneer preparation?
Margins should be in enamel, not dentine.
How deep should the preparation be for a ceramic veneer?
- 0.3mm cervical (where enamel is thinnest)
- 0.5mm
- 0.5-0.7mm incisally
Where should the proximal finishing line be for a ceramic veneer?
Between the labial and palatal surfaces, hides the margin.
Do not extend beyond the contact points! Keep contact points intact.
How much incisal edge reduction is required for a ceramic veneer?
0.7-1mm if reduction is necessary.
Describe the steps for an anterior veneer preparation (bevel).
- Chamfer bur to reduce incisal edge by 0.7-1mm
- 2 plane labial reduction using chamfer bur
- Margin should be 0.5mm from cervical margin
- Bevel incisal-buccal interface
- Create proximal margins using chamfer bur, keep contact point intact
- Reduce any high spots
- Refine proximal margins with fine needle bur
- Make final refinement with a red band (fine grit) flame composite finishing bur
What materials can be used for anterior veneers?
- Composite
- Porcelains: Emax (aka lithium disilicate) and Zirconia
- Alumina
What are the advantages and disadvantages of composite veneers?
- Repeatably repairable chairside
- Shade changeable over time, e.g. can add a lighter shade
- Stains
- Loses lustre
However, can be polished quite a lot before the intergrity of the composite is lost.
What are the advantages and disadvantages of porcelain veneers?
- High lustre and stain restistance
- Wear resistant
- More fracture resistance
- Difficult to repair
- Poor flexural strength until bonded
- Failure requires remaking veneer, requires anoth prep (more tooth destruction)
What are the key tips to remember for successful veneers?
- Limit prep to enamel only, best for bonding and less destructive
- Don’t trial fit veneer to a stone model, dust affects the bond strength and veneer will need cleaning by lab
- Proper moisture control is imperative
- Follow cementation instructions fully
- Avoid touching the fit surface or cementation material with latex gloves, latex reduces bond strength
- Ceramic veneers are relatively fragile until bonded, be careful when handling, seat with continual low pressure to allow flow of the luting agent
What is the final veneer shade dependent on?
- Ceramic shade
- Luting cement
- Underlying tooth
