Comparison of Fracture Resistance of CAD/CAM Interim Dental Bridge and Conventional Interim Resin Dental Bridge

Evaluate and compare the fracture resistance between CAD/CAM interim dental bridges and conventional interim resin dental bridges. Ideal model of full dental arch was used as a pattern to simulate three units dental bridge with (maxillary first molar and maxillary first premolar) as abutments. This model was then duplicated and resulted cast sectioned by separation disc to produce a small cast that limited to the prepared dental bridge area only. This cast was then duplicated and resulted mold poured by molten wax to produce wax pattern that was modified before casting with the use of radial shoulder finishing line design instead of chamfer finishing line that came with the original ideal model. From this wax pattern, metal master model was produced by casting using lost wax technique. Thirty two impressions for master model with two stage putty-wash impression technique were taken and poured with die stone to produce thirty two stone models. The results showed that the highest mean value of fracture resistance was recorded by Group 1 (735.9N) followed by Group 3 (585N), Group 2 (508.8N) and Group4 (460.8N) respectively. Concerning fracture mode, the connector area showed the weakest and most frequent area of fracture.