Influence of Material Selection on the Marginal Accuracy of CAD/CAM-Fabricated Metal- and All-Ceramic Single Crown Copings
Zitierfähiger Link (URL): http://resolver.sub.uni-goettingen.de/purl?gs-1/15103
This study evaluated the marginal accuracy of CAD/CAM-fabricated crown copings from four different materials within the same processing route. Twenty stone replicas of a metallic master die (prepared upper premolar) were scanned and divided into two groups. Group 1 (𝑛� = 10) was used for a pilot test to determine the design parameters for best marginal accuracy. Group 2 (𝑛� = 10) was used to fabricate 10 specimens from the following materials with one identical CAD/CAM system (GAMMA 202, Wissner GmbH, Goettingen, Germany): A = commercially pure (cp) titanium, B = cobalt-chromium alloy, C = yttria-stabilized zirconia (YSZ), and D = leucite-reinforced glass-ceramics. Copings from group 2 were evaluated for the mean marginal gap size (MeanMG) and average maximum marginal gap size (AMaxMG) with a light microscope in the “as-machined” state. The effect of the material on the marginal accuracy was analyzed by multiple pairwise comparisons (Mann–Whitney, 𝑈�-test, 𝛼� = 0.05, adjusted by Bonferroni-Holmes method). MeanMG values were as follows: A: 46.92 ± 23.12 𝜇�m, B: 48.37 ± 29.72 𝜇�m, C: 68.25 ± 28.54 𝜇�m, and D: 58.73 ± 21.15 𝜇�m. The differences in the MeanMG values proved to be significant for groups A/C (𝑝� = 0.0024), A/D (𝑝� = 0.008), and B/C (𝑝� = 0.0332). AMaxMG values (A: 91.54 ± 23.39 𝜇�m, B: 96.86 ± 24.19 𝜇�m, C: 120.66 ± 32.75 𝜇�m, and D: 100.22 ± 10.83 𝜇�m) revealed no ignificant differences. The material had a significant impact on the marginal accuracy of CAD/CAM-fabricated copings.