Aesthetic principles and composite bonding Flashcards
(22 cards)
What are the 5 factors contributing to the appearance of teeth?
outline form
contour
symmetry
proportion
colour
What is the secondary anatomy composed of?
vertical macro texture - demonstrates the depth and contour of the labial surface
this also includes developmental grooves, peak is the mamelon and the trough is the valleys
What are line angles?
shows transition between inter proximal surface of tooth through the labial surface
captures harshness of light and textured appearance
shows perikymata grooves and tertiary anatomy
What is the golden proportion?
This ratio has the numerical value 0.6180339…
It is recognised as an aesthetically pleasing ratio
What does the golden ratio suggest in relation to the teeth?
no single tooth is the same width but we accept the central incisor is largest whilst the canine is smallest
– this is the golden proportion
Describe the reflection when a light beam hits a smooth opaque block
specular
How does the specular reflection on the cervical half differ to the incisal half?
cervical - high specular
incisal - low specular
What kind of filter can be used to eliminate the harshness of reflection and what does this demonstrate?
cross-polarisation filter
demonstrates true shade value of tooth by removing glare
What will happen to light beam hitting any rough surface of the tooth?
reflected light is diffused and scattered
What do natural teeth exhibit?
high specular reflection, especially when wet
diffuse reflection
translucency (light travels through)
What 3 things can happen to light when it strikes the tooth?
diffuse
absorb
transmit
What is composed of primary anatomy?
tooth shape form
What is primary anatomy dependent on?
how restoration is placed…
composite placement
sof-lex discs
coarse diamond bur (if needed)
What does secondary anatomy involve?
integration of tmamelons and line angles
What do we use in secondary anatomy?
soflex discs
enhance point
reduced speed red grit diamond bur
for surface polishing - soflex discs, polishing wheel
What do we use to add tertiary anatomy?
coarse grit diamond bur
to add perikymata grooves
How can we ensure bonding protocol is sufficient?
moisture control
following manufacturer’s instructions
optimising bond where possible
What following methods can we use for isolation?
optragate
split dam
individual tooth isolation
What are the 3 new innovations for isolation?
unica matrices
PCFE strip
mylar strip
What are some issues with the optragate isolation?
Edges of the elastic may dig in and compromise patient comfort
(usually fairly comfortable)
Pooling of saliva
Ability to lose patient compliance
Moisture when breathing
What are some issues with individual tooth isolation?
Fiddly
Multiple steps
Risk of poorly adapted emergence
Ideally require floss ties for optimum isolation
What are the benefits of using individual tooth isolation?
Absolute isolation with rubber dam increases bond strength to enamel, independent of adhesive system
Not using rubber dam reduces shear bond strength by 50%
