# Thermographic analysis of perforations in polyurethane blocks performed with experimental conical drill bit in comparison to conventional orthopedic drill bit: a preliminary study

## TL;DR

This study compares thermal effects of conical and cylindrical drill bits on polyurethane blocks, finding no significant temperature difference but a unique inverse correlation in one group.

## Contribution

The study introduces an experimental conical drill bit and investigates its thermal behavior compared to conventional orthopedic drill bits.

## Key findings

- No statistically significant difference in maximum temperature between conical and cylindrical drill bits.
- Conical drill bit showed an inverse correlation between longer perforation time and lower maximum temperature.
- Perforation time was slightly longer for the conical drill bit.

## Abstract

Conical orthopedic drill bits may have the potential to improve the stabilization of orthopedic screws. During perforations, heat energy is released, and elevated temperatures could be related to thermal osteonecrosis. This study was designed to evaluate the thermal behavior of an experimental conical drill bit, when compared to the conventional cylindrical drill, using polyurethane blocks perforations.

The sample was divided into two groups, according to the method of drilling, including 25 polyurethane blocks in each: In Group 1, perforations were performed with a conventional orthopedic cylindrical drill; while in Group 2, an experimental conical drill was used. No statistically significant difference was observed in relation to the maximum temperature (MT) during the entire drilling in the groups, however the perforation time (PT) was slightly longer in Group 2. Each drill bit perforated five times and number of perforations was not correlated with a temperature increase, when evaluated universally or isolated by groups. The PT had no correlation with an increase in temperature when evaluating the perforations universally (n = 50) and in Group 1 alone; however, Group 2 showed an inversely proportional correlation for these variables, indicating that, for the conical drill bit, drillings with longer PT had lower MT.