Aesthetics Flashcards
What options do we have to change the colour or shape of teeth?
Whitening
Microabrasion
Composite
Veneers
Crowns
What problems can we have in regards to aesthetics?
Colour
Surface texture
Symmetry
Spaces
Shape
Arrangement
How can whitening be carried out?
To all teeth:
Chairside
At home - nightguard vital bleaching
To an individual tooth:
Internal bleaching
Inside/outside bleaching
What is nightguard vital bleaching?
Effective, minimally invasive way of improving tooth shade
What does nightguard bleaching require?
Bleaching tray
Max hydrogen peroxide conc is 6%, most home bleaching is 10% carbamide peroxide - 3.6%
First application must be carried out under observation in surgery, after this patient applies gel to the tray every night and reviewed in weekly intervals to see shade
What is whitenings effect on enamel surface morphology?
Enamel pores, depressions and erosive surface alterations seen after 2 weeks of treatment.
Sensitivity is common and all effects completely reversed at three months following tx
Recommend a F mouth rinse/varnish to improve remineralisation of enamel
What is whitenings effect on bonding?
Significant reduction in dentine bond strengths - wait at least 2 weeks post bleaching
What is non vital bleaching?
Done to brighten root filled teeth that have darkened due to pulpal remnants breaking down (bilirubin), pigmented bacteria and caries
What are two ways of treating root filled teeth that have darkened?
Internal bleaching
Inside outside bleaching
How is internal bleaching carried out?
Remove coronal restoration
Take GP down to 2mm below CEJ
Clean walls with ultrasonic
Place 1mm RMGIC over GP (not on walls)
Acid etch for 30 s
Place pledget of cotton wool soaked in carbamide peroxide
Temorary restoration with high contrast material such as poly F or chemfil rock
Review and refresh or remove and restore
What is inside outside bleaching?
Tooth prepared with GP taken down to 2mm below CEJ and RMGIC over GP, left open and provide bleaching tray.
What is microabrasion?
The use of acid etch and pumice to remove surface stains and superficial enamel defects
Can be used in cases of mild fluorosis
Can be useful in conjunction with composite veneers or bleaching to get a better starting point - severe fluorosis.
What is the process of microabrasion?
Rubber dam, clean teeth with pumice and water and dry
Apply etch to enamel for 30s and wash and dry
Clean teeth with a further pumice and water slurry in a slowly rotating rubber cup and wash
Repeat up to 3 applications if necessary
Review at 1 month and repeat up to 3x
How can composite be used to change the shape of teeth?
Can also change shade if veneer
Close diastemas
Make teeth longer and wider
What are the advantages of using composite to change the shape of teeth?
Non destructive
No lab fees
Can alter the shape to get the right result
What are the disadvantages of using composite to change the shape of teeth?
Not irreversible
Stains over time, loses aesthetics, needs maintenance
Challenging to get aesthetics right
What are porcelain veneers used for?
More conservative approach than crowns
Hides underneath - severe discolouration etc
What are the disadvantages of porcelain veneers?
Can be very brittle and can break upon cementing
What properties does a luting cement have to have?
Dual curing - light won’t properly penetrate the veneer to polymerise it enough
Have matching shades - as veneers are so thin the shade of the cement can affect the outcome
Contain a silane coupling agent - allows a chemical bond to the porcelain
What are the indications for Rely X ultimate and scotchbond universal?
Crowns
Conventional bridges
Inlays/onlays
Veneers
Posts
What are the properties of Rely X and scotchbond?
Self adhesive dual cure resin composite
Very high bond strength to tooth and metal alloys
High compressive strength
Acceptably low film thickness
Low solubility
Build up in metal and ceramic primers (silane coupling)
What is the space needed for an MCC?
0.5mm metal
0.5mm porcelain
0.2mm opaque porcelain
Need to give the technician the right amount of space as colour can be affected
How thick does a all ceramic crown need to be?
At least 1mm thick (PJC) - only suitable for anterior teeth and have short life span
What are ways to overcome ceramic crowns being brittle?
Dentine bonded crowns
Alumina/zirconia cored crowns
Which all ceramic crown has the highest strength?
Conventional zirconia
Silica based crowns arent as strong - lithium disilicate
What are dentine bonded crowns and what are they used for?
Used for anterior teeth, less destructive than a PJC gaining strength from being bonded to the tooth like a veneer
Must be supragingival and have sound tooth tissue to bond to - unlikely
What is an alumina/zirconia core crown?
Feldspathic porcelain that gains its strength from being bonded firmly to a ceramic core
More destructive than DBC or MCC (ceramic needs to be thicker than metal)
Can hide severe discolouration and can be subgingival
Ceramic core may be zirconia or alumina
What can lithium disilicate (Emax) be used for?
Crowns, veneers, inlays, anterior bridges
How are Emax dental materials made?
CADCAM
Pressed - lost wax technique
Take shade of prep as well as crown as there is a translucency
