FACIAL ENAMEL REDUCTION
0.6 mm depth cuts are made to establish a uniform preparation and porcelain thickness.

UNIFORM FACIAL PREPARATION
A medium grit rounded diamond bur is used to remove a uniform thickness of facial enamel by joining the depth-cut groves.

UNIFORM FACIAL PREPARATION
The depth of the grooves are joined in three planes by angling the diamond bur to the corresponding gingival, middle, or incisal plane of the tooth.

CHAMFER MARGINS
Correct preparation of the chamfer margins interproximally allow the appropriate bulk of porcelain.

INTERPROXIMAL EXTENTION
Using the same diamond bur, the interproximal preparation is extended from the gingival chamfer into the proximal space.

INCISAL PREPARATION
The diamond bur is angled to bevel back the incisal edge.

LINGUAL REDUCTION TO INCREASE LENGTH
The diamond bur is angled to eliminate undercuts and establish a deep chamfer on the lingual aspect of the preparation to ensure a passive fit. The incisal should be rounded. Avoid sharp line angles.

ANTERIOR CROWN PREPARATION

POSTERIOR CROWN PREPARATION

PREMOLAR INLAY PREPARATION

MOLAR ONLAY PREPARATION