Thesis (M.Sc.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Prosthodontics

Ceramic laminate veneers are now considered the restoration of choice for better aesthetics in numerous clinical circumstances. Marginal discrepancy is one of the common challenges in CAD/CAM indirect restoration especially laminates. Fracture is a clinical failure modality for ceramic laminate veneer that may be effected by the ceramic material, the preparation design and the ceramic surface treatment. The principle aim of this investigation was to evaluate the effect of preparation design of tooth and two CAD/CAM ceramic materials on marginal adaptation and fracture resistance of laminate veneers restorations. Thirty extracted human sound maxillary central incisors were selected and divided into two main groups according to the type of the CAD/CAM ceramic material used: group I: IPS Emax CAD and group II: Vita Enamic. Each group was then sub-divided into three equal sub-groups according to different preparation designs for laminate veneer restoration. Specimens of subgroup (A) were prepared with a featheredge design, specimens of subgroup (B) were prepared with butt-joint design and specimens of subgroup (C) were prepared with an incisal wrap around design. A standard preparation for the samples (0.5mm) was done using three-wheel depth cutter stone. Then pre-operative rubber index was used which acted as a templet for the amount of preparation. The CEREC Omnicam was used in scanning the prepared teeth then the data was sent to CEREC AC software 4.4 where the restorations were designed to be then sent to the milling system (CEREC MC XL) were milling process took place. All Emax CAD laminates were then glazed and fired, and Vita Enamic laminates were manually finished and polished. Then all veneers were surface treated and silanated ready for cementation. The enamel of the prepared teeth was also treated. Each laminate veneer was luted to its corresponding prepared tooth with a light cure adhesive rein cement (RelyX Veneer) and all specimens were sent to be assessed for marginal adaptation and fracture resistance individually

Issued also as CD