Heat Generation and Temperature Control during Bone Drilling for Orthodontic Mini-Implants: An In Vitro Study

Abstract

Background: The purpose of our in vitro study was to evaluate the impact of different irrigation fluid temperatures in combination with different drilling speeds on intraosseous temperature changes during mini-implant site preparation. Methods: Porcine ribs were used as bone specimens. Grouping determinants were as follows: irrigation fluid temperature (10 and 20 °C) and drilling speed (200, 600, 900, and 1200 RPM). The axial load was controlled at 2.0 kg. Temperature measurements were conducted using K-type thermocouples. Results: Extreme increments were observed only in the unirrigated groups. Irrigation invariably made a significant difference within groups defined by the same drilling speed. The comparison of the different temperature irrigation fluids (10 and 20 °C) in combination with the same drilling speed (200, 600, 900, or 1200 rpm) resulted in a statistically significant difference between the two different temperatures, whereas the use of irrigation fluid at a controlled room temperature of 20 °C showed significantly higher temperature changes. Conclusions: Based on the results of the study, we conclude that irrigation while preparing a pilot hole for a self-tapping orthodontic miniscrew is of utmost importance, even at low drilling speeds. The temperature of the cooling fluid does influence local temperature elevation to a significant extent.