Veneer
·When conditions permit,the preparation should be in the enamel layer
·Preparetion of the cutting edge can not be localed in a static or dynamic occlusal surface
·Neck region or lip thickness was prepared 0.6mm the above
·Margin thickness prepared 0.7mm the above.
Front crown
·Grooves must be rounded edge of the wall or shoulder.
·Preparation shoulder width of at least 1mm
·The cutting edge having a thickness of about 1.5mm
·Having a thickness of buccal or lingual region of about 1.2mm
Inlay
·Preparation depth of at least 1mm.
·Fissure width separating edge region at least 1mm.
·Preparation of the adjacent wall surface at an obtuse angle,The angle between the wall and the Inlay caries contact surface to 100-120 degrees.
·Not prepared and feathering feathered edges.