Comparison of the marginal discrepancy of metal and zirconia frameworks produced from various methods on different finish line configurations

The aim of this study was to evaluate the marginal adaptation of metal and zirconium frameworks on different finish line configuration produced from various manufacturing methods using 20 stainless steel dies 10 with shoulder and 10 withchamfer finish line including 6 mm crown height and 3 degree axial angle simulating the prepared tooth. After embedding the each group of die into the arc-shaped waxblocks, impressions were made using silicon based impression material and 120 models were prepared subsequently. The dies were divided into six groups each having 20 samples (10 with shoulder, 10 with chamfer finish line). Group 1 consisted of Co-Cr produced by conventional casting procedure, group 2 of Co-Cr prepared by metalmilling, group 3 of Co-Cr prepared by direct laser metal sinterization (DLMS), group 4of Zirkonzahn prepared from Y-TZP blocks using manuel designs, group 5 of Lava Zirconia produced from presinterized Y-TZP blocks using CAD-CAM and group 6 ofDC-Zirkon prepared from fully sinterized Y-TZP blocks using CAD-CAM. Stereomicroscope were used to evaluate the marginal adaptation of frameworks and marginal gap values obtained from the images were analyzed using Mann Whitney U Test and Kruskal Wallis H Test with Bonferroni correction.According to the results, in both finish lines, the lowest value of marginal gap was identified in the samples from the Lava group and the highest value was identified in those from Zirkonzahn. Marginal gap values of all groups were found to be within clinically acceptable limits.Key Words: Finish Line, CAD-CAM, Marginal Adaptation, Different Metal Frameworks, Zirconium Frameworks