OWN - Quintessenz Verlags-GmbH CI - Copyright Quintessenz Verlags-GmbH OCI - Copyright Quintessenz Verlags-GmbH TA - Int J Prosthodont JT - The International Journal of Prosthodontics IS - 1942-4426 (Electronic) IS - 0893-2174 (Print) IP - 6 VI - 9 PST - ppublish DP - 1996 PG - 525-531 LA - en TI - Effect of Cobalt-Chromium Alloy Surface Casting on Resistance to Deflection Fatigue and Surface Hardness of Titanium FAU - Vallittu, Pekka K. AU - Vallittu P FAU - Luotio AU - Luotio CN - AB - This study investigated the resistance to deflection fatigue and surface hardness of grade 2 titanium bar samples to a protion of which a layer of cobalt-chromium alloy was cast under standard dental laboratory conditions. The uncovered part of the titanium bar was deflected, and the number of loading cycles required to cause a fatigue fracture in the titanium bar was recorded. The Vickers hardness of the titanium bar was measured, and the fracture surface was examined by scanning electron microscope and energy-dispersive spectroscopy. The number of loading cycles was considerably lower in bars with the cobalt-chromium surface cast (83 vs. 13.770 cycles) (P < .001), while the surface hardness of the titanium bar with the cobalt-chromium surface cast was higher than that without the surface cast (Vicers hardness number 329 vs. 178) (P < .001). These findinfgs suggest that the cobalt-chromium surface cast dramatically affects the fatigue resistance of pure titanium, which should be considered when novel implant-supported prostheses made from premanufactured titanium parts are planned. AID - 848033