shade assessment and lab communication

Question 1

What does an aesthetic restoration consider?

Answer 1

Shape
Colour
Surface texture
Translucency

Question 2

How can you communicate shape?

Answer 2

Use adjacent teeth
If tricky- multiple teeth- still use other teeth, use study cast before preps, old photos
Diagnostic wax ups (enables planning of shape/aesthetics/tooth reduction/occlusal contacts/OVD)

Question 3

How can you communicate colour?

Answer 3

Subjective shame assessment
-colour perceived is determined by illuminant, object and observer
-complications- lighting conditions, strong distracting colours, colour variation in tooth, translucency variation, surface reflection, your colour perception

Objective shade assessment
eg. Vita Easy Shade Colourimeter
-shines consistent light at tooth, measures light reflected back and converts into shade
-not great- has variation
eg. Shade vision (X-rite) digital image
-image analysis, maps out ceramic shades
-not perfect

Question 4

How can you describe colour?

Answer 4

Vita shade guide
Munsell colour system=
Hue (colour families), chroma (saturation), value (gray scale)
Increasing value= more white

CIE colour space- gives dimension to colour and allows you to plot hue, chroma and value
- L*a*b*

Question 5

What is the classic shade guide?

Answer 5

Arranged by hues- so A= reddish yellow etc
Should arrange in order of value as eyes can better tell the difference
Not very good as doesn’t cover whole range of colour space and not evenly distributed (so mixing shades won’t create a perfect half shade)

Question 6

What is the 3D shade guide?

Answer 6

Equal distribution of shades in colour space with logical construction

Right to left is increase in value
Down is increase in chroma
Within groups there is slight hue shift

1. Determine value (M groups only)
2. Determine chroma (work down this group)
3. Determine hue (L- yellow and R- red groups)

Question 7

How can you communicate surface texture?

Answer 7

Take photo
Do a study cast
Do a try in

Tooth features- grind zone, distal and mesial line angles, depressions, central lobe

Question 8

How do you communicate translucency?

Answer 8

Highlight where translucency should be on a photo

Question 9

What are shade taking tips?

Answer 9

Hydrated teeth
Switch off operating light
Multiple light source- daylight corrected
Multiple opinions
Work quickly (eyes fatigue quickly)

Question 10

How can you communicate everything to the lab?

Answer 10

Planning- wax up, occlusion etc
Pt communication
Pre op impression
Inter occlusal record
Lab card
Shade