Comparative evaluation of surface roughness in cobalt–chromium alloy castings fabricated by different manufacturing techniques and influence of positive pressure investment technique on its surface roughness – An in vitro study

Co-Cr samples produced using computer-aided design-computer-aided manufacturing (CAD-CAM) milling (subtractive manufacturing) had the smoothest surfaces, followed by those made through the lost-wax technique with increased positive pressure. Whereas, samples fabricated using three dimensional printing (additive manufacturing) exhibited the highest Ra among all methods. The study also highlighted that samples produced under increased pressure had less Ra compared to those fabricated under normal atmospheric pressure using the conventional lost-wax technique.