Evaluation of marginal adaptation of Co-Cr-Mo metal crowns fabricated by traditional method and computer-aided technologies

J Dent Sci. 2019 Sep;14(3):288-294. doi: 10.1016/j.jds.2018.11.006. Epub 2019 Mar 25.

Abstract

Background/purpose: The purpose of this study was to evaluate the marginal gaps of dental restorations manufactured using conventional loss wax and casting, computer-aided design/computer-aided manufacturing (CAD/CAM), and 3D printing methods.

Materials and methods: A zirconia master die model with an upper right first molar resin crown was prepared as a standardized model. A total of 30 resin master die models were duplicated from this standard model. Simultaneously, 10 Co-Cr-Mo metal crowns were individually obtained using the conventional loss wax and casting method (Group A), selective laser sintering (Group B), and CAD/CAM (Group C), respectively. The marginal gaps between the crowns fabricated conventional and digital methods with master die models were calculated using a 3D replica and mapping technique.

Results: Statistical analyses revealed there were significant differences in the marginal gaps in the group A with group B and C (p < 0.05). The mean marginal gaps between dental crowns with die models were 76 ± 61 μm, 116 ± 92 μm, and 121 ± 98 μm for groups A, B, and C, respectively.

Conclusion: Within the limitations of this study, the marginal gaps were clinical acceptable in conventional and digital techniques.

Keywords: Computer-aided design/computer-aided manufacturing; Conventional lost wax and casting method; Direct metal laser sintering; Marginal adaptation.