الفهرس 
ACKNOWLEDGEMENTOnly 14 pages are availabe for public view
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Abstract
The adverse effects of a crown preparation on the vitality of the pulp tissue have been well documented weakening the teeth, destroying valuable dental tissues and causing severe biological reactions in the dental pulp. Inlay-retained fixed partial dentures (IRFPDs) have been proposed as a means for fixed partial denture fabrication in the patient’s mouth. To preserve vital tooth structure only a proximal box with or without an occlusal extension has been recommended in the literature. Zirconia-based IRFPDs demonstrated higher survival rates in previous studies when compared with other all-ceramic and fiber-reinforced composite IRFPDs. The aim of this study was to evaluate three different resin bonded monolithic inlay retained fixed partial denture designs made of translucent zirconium in-vitro and in-vivo.
In the in vitro study, thirty monolithic zirconia IRFPDs were constructed on extracted teeth placed in acrylic blocks with 10 mm distance between them to simulate a missing maxillary molar. The specimens were divided randomly into 3 groups according to their cavity preparation design. group 1 received in each abutment a proximal box cavity preparation with a 2 mm deep occlusal extension. group 2 received a proximal box cavity preparation with a 1.5 mm deep occlusal extension. group 3 received only proximal box preparations without any occlusal extension. The specimens were aged using cyclic loading to mimic a 5-year period in function. SEM analysis of the margins was conducted for each specimen before and after the ageing process to evaluate marginal continuity, followed by a dye penetration test to assess marginal leakage.