Internal fit of three ‐unit fixed dental prostheses produced by computer‐aided design/computer‐aided manufacturing and the lost‐wax metal casting technique assessed using the triple‐scan protocol

Suboptimal adaptation of fixed dental prostheses (FDPs) can lead to technical and biological complications. It is unclear if the computer‐aided design/computer‐aided manufacturing (CAD/CAM) technique improves adaptation of FDPs compared with FDPs made using the lost‐wax and metal casting technique. Three‐unit FDPs were manufactured by CAD/CAM based on digital impression of a typodont model. The FDPs were made from one of five materials: pre‐sintered zirconium dioxide; hot isostatic pressed zirconium dioxide; lithium disilicate glass‐ceramic; milled cobalt‐chromium; and laser‐sintered cobalt‐chromium. The FDPs made using the lost‐wax and metal casting technique were used as reference. The fit of the FDPs was analysed using the triple‐scan method. The fit was evaluated for both single abutments and three‐unit FDPs. The average cement space varied between 50 μm and 300 μm. Insignificant differences in internal fit were observed between the CAD/CAM‐manufactured FDPs, and none of the FPDs had cement spaces that were statistically significantly different from those of the reference FDP. For all FDPs, the cement space at a marginal band 0.5–1.0 mm from the preparation margin was less than 100 μm. The milled cobalt‐chromium FDP had the closest fit. The cement space of FDPs produced using the CAD/CAM technique was similar to that of FDPs produced using the conventional lost‐wax and metal casting technique.
Source: European Journal of Oral Sciences - Category: Dentistry Authors: Tags: Original Article Source Type: research