The effects of operator technique and bur design on temperature during osseous preparation for osteosynthesis self-tapping screws

Objective. Although the importance of atraumatic preparation of bone before the placement of osseointegrated implants has long been emphasized, the situation during placement of self-tapping screws has received little attention. Because the production of excessively high temperatures during osseous drilling is known to impair bony regeneration, the strict thermal criteria that are set for implant placement should theoretically be extended to trauma and orthognathic internal fixation. Study design. Temperatures achieved during the drilling of thawed human cadaveric bone before the insertion of osteosynthesis self-tapping screws were measured in vivo with thermocouples. Combinations of 2 drilling systems and 2 bur designs were studied. Variations in surgical technique were incorporated by altering both the force applied by the operator and the application of irrigant. Statistical significance was examined through use of a Student t test. Results. One of the 2 bur designs and careful operator technique were associated with significantly smaller increases in temperature. Irrigation had the greatest effect on temperature recorded, the absence of irrigant resulting in temperatures in excess of 70 degrees C. Conclusions, These findings emphasize the importance of careful surgical technique and constant irrigation during osseous preparation ii the potential for bone regeneration around osteosynthesis self-tapping screws is to be maximized.