Evaluation of Vertical Marginal Discrepancy of Conventional Cobalt-Chromium and a Novel Base Metal Casting Alloy, Heraenium-S, with Two Different Finish Lines before and after Porcelain Firing: A Photomicroscope-Based, In Vitro Study

Background: The success of cast restorations depends upon the fit of the casting framework to the underlying tooth structure. Objective: This study aimed to evaluate the vertical marginal discrepancy of conventional cobalt-chromium and a novel base metal casting alloy, Heraenium-S, with two different finish lines before and after porcelain firing. Materials and Methods: For this study, a total of 40 copings were made for four groups, with 10 copings in each group consisting of the conventional cobalt-chromium and novel base metal casting alloy, Heraenium-S, with two different finish lines. The methodology adopted for this study included standard, conventional techniques for the fabrication of cast copings, while this was followed by assessment of the vertical marginal gaps and/or discrepancies using a specialized photomicroscope at 50× magnification before and after porcelain firing. Results: This study revealed statistically significant to highly significant variations in the mean vertical marginal discrepancy values between the two base metal alloys when used with two different finish lines, both before and after porcelain firing. Conclusions: Based on the observations made, it was concluded that the vertical marginal gaps in the case of the castings used with the chamfer finish line had significantly higher values than when used with the shoulder finish line, both before and after porcelain firing. Although the alloy type used influenced these microscopic gaps, the mean gaps and discrepancies were found to be within clinically acceptable limits.