The effect of irrigation on osteotomy depth and bur diameter.

A device to measure bur temperature using thermocouple technology was developed. A block of bovine bone was subjected to computerized tomography scanning to confirm bone density and configuration similar to that of a human mandible. Bone temperature was measured via a thermocouple probe. During osteotomy preparation, bur temperature was shown to exceed the surrounding bone temperature. Irrigation greatly reduced bur temperature. Osteotomies were made to depths of 8.5, 10.5, 13.5, 15.5, 18.5, and 20.5 mm. Bone density played a far greater role in bur temperature elevation than did osteotomy depth. Adding a pilot drill to the drill sequencing tended to lower bur temperature; widening of osteotomies from 2 to 3 mm wide generated as much heat as did the making of the 2-mm-wide osteotomy.