A Comparison of Thermal Changes among Four Different Interproximal Reduction Systems in Orthodontics

Interproximal enamel stripping is routinely used in orthodontics, different methods were utilized by clinicians to reduce the width of teeth but no previous study addressed the factors affecting the thermal safety of such systems on the dental pulp.

The present study was conducted to measure thermal changes among four different interproximal reduction (IPR) systems in orthodontics.

A total of 130 extracted human premolar teeth were used in this study. Teeth were distributed into three experimental groups each having three subgroups and one control group. Thus, a total of 10 subgroups were created of 13 teeth each. Stripping procedures were performed using four diamond tools (burs, discs, saw, and manual strip) with different speed setup, with and without a coolant for the higher speed setup for each tool. A K-type thermocouple wire was positioned in the center of the pulp chamber and was connected to a data logger during the application of stripping procedures. Data were analyzed by the Krushkal-Wallis test using the SPSS PC+ version 21.0 statistical software.

There was a highly statistically significant difference in the mean ranks of temperature values among the four groups with different speed levels. Among the 10 subgroups, the higher change in temperature registered was in the bur and disc groups when operated with the highest recommended speed without a coolant. The change in temperature was statistically significantly higher than the temperature values of other groups (p < 0.001). All recorded temperatures were below the critical temperature (5.5 °C) registered.

Based on the results of this study, IPR is a safe procedure on the dental pulp for the teeth with a medium dentin thickness with or without a coolant.