الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
The wax or acrylic pattern is a prerequisite for the finished cast restoration being placed on the prepared tooth or teeth, i.e. the pattern will be duplicated exactly by the processes of investing and casting into the final restoration. Therefore, the final restoration depends greatly on the accuracy of the pattern. Materials and Methods: A total of 30 samples were constructed for this study. 15 as frameworks for single unit cast restoration, while the other 15 were copings for three unit fixed bridges. Grouping of samples: The samples were divided into three main groups according to the type of pattern material used for the construction of the cast restorations Group A: Machinable acrylic resin patterns. Group B: Machinable acrylic resin patterns with waxed margin. Group C: Wax patterns. Each group was further divided into two subgroups according to the type of cast restoration, Subgroup I: Single unit restorations. Subgroup II: Three unit restorations. Results: It was found that single unit castings made using wax patterns exhibited the lowest marginal gap distance mean value (28.86μm), followed by those done using CAD-Waxx with waxed margins (33.63μm). Finally castings made using CAD-Waxx blocks showed the highest marginal gap mean value (39.23μm). Similarly three unit wax pattern castings showed the lowest marginal gap distance mean value (29.81μm), followed by the CAD-Waxx with waxed margin group (46.71μm), while the CAD-Waxx group showed the highest marginal gap distance mean value (48.86μm).