AN IN VITRO STUDY TO EVALUATE THE SURFACE ROUGHNESS AND BOND STRENGTH OF PORCELAIN FUSED TO METAL RESTORATIONS FABRICATED BY DIFFERENT METHODS

Aim: The aim of the study was to evaluate the surface roughness and bond strength of porcelain fused to metal restorations fabricated by different methods. One hundred and twenty bar shaped samples of cobalt-chromium were fabricated by centrifuga Materials and Methods: l casting, induction casting, direct metal laser sintering and milling containing thirty samples each. These samples were further divided into subgroups of which ten samples were served as control, ten samples were surface treated with Aluminium oxide particles, ten samples were surface treated with Silicon carbide particles. Samples were tested for surface roughness using Profilometer. Then samples were fired with porcelain and bond strength was measured using Universal testing machine. Results were analyzed using one-way ANOVA followed by Tukey multiple comparison test. Results: There was statistically significant difference among all four groups. The highest bond strength was seen in direct metal laser sintered samples followed by milling and induction casting and the least was found in centrifugal cast samples. Surface roughness was found highest in the samples abraded with silicon carbide particles followed by aluminium oxide particles. Within the li Conclusion: mitations of the study, it can be concluded that laser sintered Co-Cr frameworks establish a strong bond with porcelain and also the metal-ceramic bond strength is dependent on the manufacturing method used and it was found that the bond strength values of all samples exceeded the minimum acceptable value of 25 MPa recommended by the ISO 9693.