ABSTRACT
The aim of this work was to evaluate the Cerec 1, Cerce 2 and the conventional porcelain laminate veneers in terms of fit, microleakage and shear bond strength to the tooth surface. Thirty maxillary central incisors were used for the fit and microleakage tests. They received standardized preparations and were divided into three groups of ten each. Group 1, 2 and 3 were restored with Cerec 1 Cerce 2, and conventional laminate veneers respectively. Alter staining and thermocycling, the teeth with their bonded laminates were sectioned by two cuts [incisogingivally and misiodistally]. Fit and microleakage were evaluated by measuring the cement thickness and degree of dye penetration respectively using an image processing computerized stereomicroscope. For the assessment shear bond strength thirty other central incisors received flat preparations in enamel. Thirty porcelain specimens were fabricated using the above systems [ten specimens each] then bonded to the prepared enamel surface. After themocycling, a shear test was done using a universal testing machine. The debonded surface were then observed under a scanning electron microscope. Overall, the Cerec 2 CAD-CAM laminate veneers did overcome many of the disadvantages found in the Cerec 1 laminate veneers. The quality of the laminate veneers produced by the Cerec 2 CAD-Cam unit is comparable to the conventional laminate veneers