ABSTRACT
The aim of this study was to assess the internal and marginal discrepancies of chromium-cobalt (Co/Cr) copings fabricated using different techniques. A typodont molar tooth was prepared and replicated in die stone and scanned. Forty Co-Cr alloy copings were produced using four different production techniques: conventional casting (Cgroup), direct metal laser sintering (DMLS-group), micro-stereolithography/casting combination (µSLA-group), and computer-aided milling (M-group) (n = 10). The internal and marginal discrepancies at various reference points were determined via digital microscopy. Analysis of variance (ANOVA) and Tukey's multiple comparisons tests were used for statistical analysis (p=0.05). The marginal and cervical discrepancies of the C-group were similar to those of the M-group (p⟩0.05) and better than those of the µSLA-group (p⟨0.05). The marginal and internal discrepancies of all groups were within clinically acceptable limits, but further improvements in the µSLA and DMLS techniques may be required prior to clinical implementation.