Shade guides• Shade tabs

- Each shade guide consists of multiple shade tabs

Vita Lumin VacuumStep 1: Hue matching

- Four grouping of hue,

A1-A4 Reddish-BrownishB1-B4 Reddish-YellowishC1-C4 Grayish shadesD2-D4 Reddish-gray

- Match the samples with high chroma with cervical area of canines

Vita Lumin VacuumStep 2: Chroma selection

- Once the hue has been accomplished, a choice is made for the best chroma

- For instance B is the best hue match then it has four different chroma: B1, B2, B3, B4, of the same hue

Vita Lumin VacuumStep 3: Value selection

- Finally, value is determined with a second commercial guide whose samples are arranged in increasing lightness (B1-C4)

- An observer will be able to assess the value most effectively by observing from a distance, standing slightly away from the patient, and looking through a squinted eye, reducing the light that reaches the retina. Stimulation of the cones is reduced and greater conditions to achromatic vision may result

Vita Pan 3D Master

• There are 5 lightness levels (plus an additional level for bleached teeth)

Vita Pan 3D Master

Step 1: Value

- Select one out of the 5 value groups

Vita Pan 3D Master

Step 2: Chroma

- Choose the appropriate chroma by using the M subgroup first and choosing between level 1, 2 or 3

Vita Pan 3D Master

Step 3: Hue

- Choose the appropriate hue by choosing either more reddish (R) or more yellowish (L)

- Available in two chroma for group 2, 3 & 4

Shade guides• Other available systems,

- Extended shade guides

- Dentin shade guide

- Custom shade guide

Instrumental color analysis

• Inconsistencies can result from factors such as physiological, psychological, age & fatigue

• Instrumental color analysis is an alternative offering objective, quantifiable & more rapidly obtained shade matching

• Various color measuring instruments exist: colorimeters, spectrophotometer, and digital image analyzers

Instrumental color analysis

• Colorimeters, spectrophotometer are unsuitable for routine dental use because of their limited ability to measure the color of translucent objects

• In addition, colorimeters are adapted for flat surfaces and not curved teeth surfaces

Instrumental color analysis

Surface characterization• Stains can be added to the surface of the restoration to produce better tooth integration & natural appearance

• Used only for minor changes, to achieve:

1. Shade modification2. Specific characterization3. Special illusions of form or

position

Shade distribution chart

• The tooth is divided into three regions: cervical, middle & incisal

Surface characterization• Advantages

- Dentist can modify the shade after completion of

the restoration

• Disadvantages

- Stains are applied to the surface only

(unrealistic)

-If excessive can cause loss of fluorescence &

increased metameric effect

- Restoration becomes slightly rougher

- Stains are soluble & wear with time

Shade modification

a. Chroma & Hue adjustments

• Increasing chroma and changing hue

• Pink purple moves yellow toward yellow red, yellow decreases red to yellow red

• If we desire to decrease the chroma we usually use the complementary colors (yellow requires blue-purple & orange, blue-green) however rarely successful

Shade modification

b. Value adjustments

• Can be reduced by adding complementary color (violet for yellow)

• Increase the value if the dominant color has a greater lightness such as staining with white but the opacity will increase & rarely successful

Specific characterization

• Hypocalcified areas• Proximal colorations

• Enamel cracks• Stained crack lines

• Exposed incisal dentin• Incisal halo

• Translucency

Specific characterization

Thank you