No abstract

Purpose: The bond strength of metal ceramic restorations places a key role for the longevity of the prosthesis which could be affected by the fabrication technique and the number of firings. The current research evaluates the effect of repeated firings on bond strength of metal ceramic systems with copings fabricated from two processing techniques, lost wax technique through induction casting and direct metal laser sintering. Materials and Methods: 21 metal ceramic bars will be fabricated using Direct Metal Laser Sintering (Group DMLS) and 21 using conventional lost wax technique (Group Cast). Each sample will have a dimension of 25x3x0.5mm respectively. In the center of each bar, a 1.1mm thickness of porcelain will be fused onto an 8x3mm rectangular area. Each group is further subdivided into 3 subgroups which are subjected to repeated firings (3, 5, 7) and the bond strength is measured with positioning of the samples on a Universal Testing Machine. Results: Group ANOVA and Post Hoc Tukeys test showed comparison of overall bond strength of ceramic samples fabricated using DMLS & Casting subjected to different Firing was done and the difference in mean was statistically significant (p<0.05). Conclusion: The DMLS group showed slight superior bond strength properties when compared with Cast group.