Comparison of Marginal and Internal Adaptation of CAD/CAM and Conventional Cement Retained Implant-Supported Single Crowns

Abstract

PURPOSE: To evaluate the accuracy of marginal and internal adaptation of 2 computer-aided design/computer-aided manufacturing (CAD/CAM) and 2 conventionally made cement retained implant-supported restorations. MATERIALS AND METHODS: An abutment and its corresponding fixture analog (Astra Tech) were inserted in left central incisor area of a maxillary cast. Four types of implant-supported single restorations were fabricated on the abutment (n = 10): e.max CAD (Cerec AC system), zirconia-based (Cercon system), IPS e.max Press, and metal-ceramic restorations. The internal and marginal gaps of the studied groups were measured by replica method and stereomicroscope. Data were subjected to 1-way ANOVA and Scheffe post hoc tests (alpha = 0.05). RESULTS: Mean internal gaps of Cercon (59.48 +/- 16.49 mum) and e.max Press (75.62 +/- 26.92 mum) groups were significantly different from e.max CAD (120.29 +/- 16.74 mum) group, but there was no significant difference between metal-ceramic restorations (89.65 +/- 47.84 mum) and e.max CAD. The marginal gaps of e.max CAD (32.02 +/- 10.38 mum) and Cercon restorations (34.26 +/- 11.41 mum) were significantly superior from metal ceramics (59.19 +/- 17.81 mum) and e.max press (74.99 +/- 24.51 mum). CONCLUSION: Within the limitations of this study, it can be concluded that although the marginal and internal gaps of the studied implant-supported restorations were in the clinically acceptable range, single crowns made with CAD/CAM technology provide better marginal fit.