METAL - CERAMIC BOND STRENGTH ANALYSIS OF COBALT-CHROMIUM DENTAL ALLOY FABRICATED BY THREE DIFFERENT TECHNIQUES (IN-VITRO STUDY)

INTRODUCTION Cobalt-chromium alloy is used widely for fabrication of dental fixed prostheses (1). The metal framework of the restorations can be fabricated by different techniques including, conventional lost wax, subtractive (CAD-CAM milling) and additive (selective laser sintering) manufacturing technologies (2). METHODOLOGY Forty-two Co-Cr specimens (25mmx3mmx0.5mm) were prepared according to ISO 9693:1999 standards using three different techniques: selective laser sintering (group1, n=14), CAD-CAM milling (group2, n=14) and lost wax technique (group3, n=14). The metal bars were veneered by firing a porcelain layer on the center of each specimen (8mm length x3mm width x1.1mm thickness), metal ceramic bond strength was evaluated by a three-point bending test then each specimen was examined by Scanning electron microscope to evaluate the failure mode (Figure 1).