RESUMO
BACKGROUND: Atraumatic preparation of the osteotomy site is critical for osseointegration. PURPOSE: This study aimed to investigate the effects of multiple usages of dental implant drills on bone temperature changes and to examine the cutting surfaces of these drills under a scanning electron microscope (SEM). MATERIALS AND METHODS: The implant osteotomy procedure was adapted to the experimental setting to simulate wear on implant drills by preparing bovine ribs using a constant drilling force. Thermocouples were placed in the specimens to record temperature changes. SEM images of the drills were taken, and elemental spectroscopic analysis was performed. RESULTS: Temperatures measured in the bone adjacent to the implant site did not exceed 27.7°C during the experiment. Spectroscopic elemental analysis indicated that two of the drills were of a stainless steel composition, and the other drill consisted of a tungsten carbide-coated stainless steel. The tungsten carbide-coated bur had the lowest overall drilling temperatures and showed the least surface corrosion and plastic deformation. SEM analysis showed degradation of the cutting surfaces of the burs although the plastic deformation and surface wear did not appear to affect the cutting temperatures. Surface corrosion was observed on the cutting surfaces. CONCLUSIONS: Drills used for up to 50 osteotomies do not appear to elevate bone temperatures to a harmful level. However, drill corrosion is potentially important in determining the life span of implant burs.
