"Effect of Retainer Design on the Mode of Failure of All Ceramic Cantilever Adhesive Fixed Dental Prosthesis"

Abstract

Two different preparations were done on teeth number 23 of the typodont model, one palatal and one labial for each design. Twenty epoxy models were duplicated resembling upper central incisors and canines, 10 epoxy models for each design. Twenty cantilever all ceramic resin bonded fixed dental prostheses were (RBFDPs) fabricated to replace a missing maxillary lateral incisor. The prostheses were divided into two groups according to the site of the retainer: i) Palatal veneer retained fixed dental prosthesis (n=10).

ii) Labial veneer retained fixed dental prosthesis (n=10).

All ceramic fixed dental prostheses were designed using Exocad software and fabricated from lithium disilicate using heat pressed technique. Then the prostheses were bonded to their corresponding epoxy resin model using dual cure resin. Fracture resistance test were performed on all specimens after thermomechanical aging with chewing simulator for 150,000 mechanical fatigue cycles of 50 N loads. Data were collected, tabulated and statistically analyzed through paired t- test.