Thesis (Ph.D.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Prosthodontics

The present study aimed to investigate the vertical marginal gap distance and fracture resistance of two conservative all-ceramic fixed partial denture (FPD) designs in comparison to conventional full coverage-retained fixed partial denture. Three models were created by mounting one cast premolar in an acrylic resin block in conjunction with one of the three cast molars with a 10 mm space between them which corresponded to the dimension of a missing first molar. Fifteen posterior full-contour zirconia-based all-ceramic FPDs were fabricated using CAD/CAM technique and divided into three groups of five samples each according to the type of retainer design:- Group (1): Inlay/inlay-retained FPDs with the inlay retainer on both the premolar and molar teeth. Group (2): Inlay/onlay-retained FPDs with a premolar inlay retainer and a molar onlay retainer. Group (3): Full coverage/full coverage-retained FPDs with full coverage retainers on both the premolar and molar teeth. For all FPDs, the vertical marginal gap distance was measured using scanning electron microscope at 400{u00D7} magnification. Each mounted chrome-cobalt dies were duplicated into five epoxy resin models for each tested FPD design. The fifteen FPDs were cemented on their respective epoxy resin models with self-adhesive self-cure resin cement. All samples were loaded and fracture loads (N) were measured at fracture with a computer controlled materials testing machine at a crosshead speed of 1.0 mm/min.

Issued also as CD