الفهرس 
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Abstract
The purpose of this study was to evaluate the marginal leakage and internal adaptation of porcelain laminate veneer using two different types of ceramics, according to fabrication technique, (pressable using lost wax technique and machinable using CAD/CAM technique) through dye penetration test.
Forty ceramic laminate veneers were fabricated by two different fabrication technique using a conventional pressable technique (group P n = 20) and a CAD/CAM fabrication technique (group M n = 20). All samples were prepared through one preparation design (overlap preparation), after fixation in acrylic blocks and construction of silicon index.
Epoxy samples were constructed to avoid the problems which encountered during teeth preparation such as cracks and enamel hypo mineralization, then veneers were fabricated (each according to its fabrication technique).
All fabricated veneers were acid etched using hydrofluoric acid, silanated, and cemented on their corresponding prepared teeth by resin cement. Then samples were stored under water (37˚C) for 60 days, then received thermocycling (15,000 cycles between 5 and 55 8C and dwell time of 90 s) followed by cyclic loading (100,000 cycles between 50 and 100 N).
Then all samples immersed in methylene blue dye for 24 h. Half of the specimens in each group were sectioned in vertical direction (n = 20), and the rest were horizontally sectioned (n = 20).
Internal adaptation (cement film thickness), and marginal gaps at the incisal and cervical regions were measured.
All data collection were tabulated and statistically analyzed.
Data were collected, tabulated and statistically analyzed with the following conclusions, within the limitations of this study:
Marginal fit and internal adaptation are of the most important criteria for the long-term success of all ceramic restorations.
The result of this literature shows that CAD/CAM systems improve the average quality of prostheses adaptation compared with that obtained with conventional manufacturing methods.
The application of CAD/CAM technology is promising for the delivery of high-quality devices in all fields of dentistry. It is esthetically pleasing, effective; time-saving and can be applied successfully in private practice.
Machinable ceramic laminate veneers produced higher marginal adaptation, homogenous and thinner cement film thickness, and improved resistance to microleakage compared to pressable ceramic veneers.