Temperature Changes during Implant Osteotomy Preparations in Human Cadaver Tibiae Comparing MIS (R) Straight Drills with Densah (R) Burs

(1) Background: Several studies showed a sustained temperature of 47 degrees C or 50 degrees C for one minute resulted in vascular stasis and bone resorption with only limited bone regrowth over a 3-4-week healing period. The purpose of the present study was to evaluate the temperature changes (Delta T) that occur during the preparation of dental implant osteotomies using MIS (R) straight drills versus Densah (R) burs in a clockwise (cutting) drilling protocol. (2) Methods: Two hundred forty (240) osteotomies of two different systems' drills were prepared at 6 mm depth at 800, 1000, and 1200 revolutions per minute (RPM), in fresh, unembalmed tibiae, obtained by a female cadaver. Delta T was calculated by subtracting the baseline temperature on the tibial surface, from the maximum temperature inside the osteotomy (Delta T = T-max - T-base). The variables were evaluated both for their individual and for their synergistic effect on Delta T with the use of one-, two-, three- and four-way interactions; (3) Results: An independent and a three-way interaction (drill design, drill width, and RPM) was found in all three RPM for the Densah (R) burs and at 1000 RPM for the MIS (R) straight drills. As Densah (R) burs diameter increased, Delta T decreased. The aforementioned pattern was seen only at 1000 RPM for the MIS (R) straight drills. The usage of drills 20 times more than the implant manufacturers' recommendation did not significantly affect the Delta T. A stereoscopic examination of the specimens confirmed the findings. (4) Conclusions: The independent and synergistic effect of drills' diameter, design and RPM had a significant effect on Delta T in human tibiae, which never exceeded the critical threshold of 47 degrees C.