Aesthetics

Question 1

What options do we have to change the colour or shape of teeth?

Answer 1

Whitening
Microabrasion
Composite
Veneers
Crowns

Question 2

What problems can we have in regards to aesthetics?

Answer 2

Colour
Surface texture
Symmetry
Spaces
Shape
Arrangement

Question 3

How can whitening be carried out?

Answer 3

To all teeth:
Chairside
At home - nightguard vital bleaching

To an individual tooth:
Internal bleaching
Inside/outside bleaching

Question 4

What is nightguard vital bleaching?

Answer 4

Effective, minimally invasive way of improving tooth shade

Question 5

What does nightguard bleaching require?

Answer 5

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

Question 6

What is whitenings effect on enamel surface morphology?

Answer 6

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

Question 7

What is whitenings effect on bonding?

Answer 7

Significant reduction in dentine bond strengths - wait at least 2 weeks post bleaching

Question 8

What is non vital bleaching?

Answer 8

Done to brighten root filled teeth that have darkened due to pulpal remnants breaking down (bilirubin), pigmented bacteria and caries

Question 9

What are two ways of treating root filled teeth that have darkened?

Answer 9

Internal bleaching
Inside outside bleaching

Question 10

How is internal bleaching carried out?

Answer 10

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

Question 11

What is inside outside bleaching?

Answer 11

Tooth prepared with GP taken down to 2mm below CEJ and RMGIC over GP, left open and provide bleaching tray.

Question 12

What is microabrasion?

Answer 12

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.

Question 13

What is the process of microabrasion?

Answer 13

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

Question 14

How can composite be used to change the shape of teeth?

Answer 14

Can also change shade if veneer
Close diastemas
Make teeth longer and wider

Question 15

What are the advantages of using composite to change the shape of teeth?

Answer 15

Non destructive
No lab fees
Can alter the shape to get the right result

Question 16

What are the disadvantages of using composite to change the shape of teeth?

Answer 16

Not irreversible
Stains over time, loses aesthetics, needs maintenance
Challenging to get aesthetics right

Question 17

What are porcelain veneers used for?

Answer 17

More conservative approach than crowns
Hides underneath - severe discolouration etc

Question 18

What are the disadvantages of porcelain veneers?

Answer 18

Can be very brittle and can break upon cementing

Question 19

What properties does a luting cement have to have?

Answer 19

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

Question 20

What are the indications for Rely X ultimate and scotchbond universal?

Answer 20

Crowns
Conventional bridges
Inlays/onlays
Veneers
Posts

Question 21

What are the properties of Rely X and scotchbond?

Answer 21

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)

Question 22

What is the space needed for an MCC?

Answer 22

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

Question 23

How thick does a all ceramic crown need to be?

Answer 23

At least 1mm thick (PJC) - only suitable for anterior teeth and have short life span

Question 24

What are ways to overcome ceramic crowns being brittle?

Answer 24

Dentine bonded crowns
Alumina/zirconia cored crowns

Question 25

Which all ceramic crown has the highest strength?

Answer 25

Conventional zirconia
Silica based crowns arent as strong - lithium disilicate

Question 26

What are dentine bonded crowns and what are they used for?

Answer 26

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

Question 27

What is an alumina/zirconia core crown?

Answer 27

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

Question 28

What can lithium disilicate (Emax) be used for?

Answer 28

Crowns, veneers, inlays, anterior bridges

Question 29

How are Emax dental materials made?

Answer 29

CADCAM
Pressed - lost wax technique
Take shade of prep as well as crown as there is a translucency