Temperature Changes during Implant Osteotomy Preparations in Fresh Human Cadaver Tibiae, Comparing Straight with Tapered Drills

The success of osseointegration depends on many factors. With temperatures beyond a 47 degrees C threshold over 1 min, bone survival may be impaired. The purpose of the study was to evaluate, in fresh human cadaver tibiae, the temperature changes during osteotomy preparations using two straight and two tapered implant systems' drills, external irrigation, and varying revolutions per minute (RPM). The tibiae from a fresh female cadaver were harvested bilaterally. Two tapered and two straight design drills were assessed. Two-hundred and forty osteotomies were prepared at 6 mm depth following the drill sequence of the manufacturers' protocol for each drilling speed. Difference in temperature (Delta tau) was calculated by subtracting the baseline from the maximum temperature (Delta T = T-max - T-base). Drill design and drill diameter, as independent variables or synergistically, had a significant effect on Delta tau. Tapered drills: As the drill diameter increased, Delta tau increased at all RPM. Straight drills: As the drill diameter increased, Delta tau remained constant or slightly decreased at all RPM. Drill diameter and design had a significant effect on Delta tau in human tibiae, which never exceeded the critical threshold of 47 degrees C. Tapered drills caused significantly greater heat production compared to straight drills.