Comparative study on AISI 440 and AISI 420B stainless steel for dental drill performance

One of the most usual causes of the failure in dental implant osseointegration is the increase of the temperature above 47 degrees C during the drilling of the bone because it produces irreversible osteonecrosis. The result is weakened contact of implants with bone and possible loss of rigid fixation. Many studies about the design of the drill bit, contact forces, drill speed, drill point angle and feed-rate have been made. However, in all studies a martensitic stainless steel (AISI 440) has been used. The aim of this study was to determine the behavior of AISI420B stainless steel with higher hardness, higher heat conductivity and lower wear than the conventional stainless steel used in oral implantology. This steel showed adequate temperature increases, with or without irrigation, and a decrease of the weight lost of the drills with use. (C) 2012 Elsevier B.V. All rights reserved.