Predictors of Infrared Thermography During Dental Preparation for Fixed Prostheses: A Linear Regression Model

Aim: To evaluate the thermal changes occurring during dental preparation for fixed prostheses using infrared thermography and identify the predictive factors influencing temperature rise through a linear regression model. Materials and Methods: An in vitro experimental design was established to use bovine incisors, chosen because their histology is like that of human teeth. The specimens were randomly grouped according to irrigation status (irrigation vs. no irrigation), bur condition (new vs. used), and bur brand (brand A, brand B, brand C), respectively. Dental preparations were performed using high-speed handpieces (300,000 RPM) with medium-grain diamond burs providing the source of irrigation at a rate of 50 mL/min. Surface temperature changes were continuously recorded by infrared thermography (Fluke TiS55+) during preparation. Results: Immediately after tooth preparation, temperatures were significantly higher under nonirrigated conditions (36.15°C ± 4.37°C) compared with irrigated procedures (20.78°C ± 0.79°C), yielding an overall mean difference of 15.37°C (95% CI: 14.24–16.51; p < 0.001). Preparations performed with previously used diamond burs generated greater thermal elevations than unused burs (mean difference: −3.24°C; 95% CI: −6.20 to −0.27; p < 0.001). Variations among bur brands were minimal and did not reach statistical significance in post hoc testing (p > 0.05), although subtle differences emerged in the adjusted regression model. Overall, temperature rise during dental preparation was strongly influenced by irrigation, whereas bur brand exerted negligible impact. Conclusion: Irrigation has been found to be the most significant factor for managing temperature changes associated with tooth preparation, with burs wear also being a contributing factor to thermal accumulation, though less significantly. The brand of bur used in the tooth preparation procedure had the least influence on the amount of thermal accumulation experienced by the tooth.