الفهرس 
Concept of Passive FitOnly 14 pages are availabe for public view
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Abstract
The research presented in this study evaluated the effect of abutment surface roughening and ceramic veneering of implant-supported fixed prostheses on passivity of fit.
A model was constructed of epoxy resin with two embedded implants to simulate a clinical situation of a missing upper first premolar, second premolar and first molar. Four strain gauges war attached to the model surface mesial and distal to the implants.
Three pairs of abutments were used; one pair was used without surface treatment, one pair was sandblasted and one pair was ground with abrasive stones. A group of 15 three-unit full veneered metal-ceramic bridges was constructed on each pair of abutments.
The evaluation of change in passivity of fit was done through measurement of strains transferred to the model through the implants after seating of the bridges under a load of 200N. Each group of bridges was seated on the corresponding abutments in the as-cast condition and measurements were recorded. The bridges were then veneered with opaque porcelain and fired, then reseated and measurements were recorded. Finally the bridges were veneered with body porcelain and glaze porcelain and fired, then reseated and measurements were recorded.
The recorded measurements were statistically analyzed to compare between strains induced in the model within each group when the bridges were as-cast, after opaque porcelain firing and after body and glaze porcelain firing. A comparison was also done between strains induced by the three groups over untreated abutments, sandblasted abutments and ground abutments.