Investigation of irrigation fluid temperature variations caused by thulium fiber laser with various settings and comparison with Ho:YAG laser: An in vitro experimental study.

Abstract

Introduction: Our experimental in vitro study aimed to evaluate the impact of four power settings with different energy and frequency combinations on the irrigation fluid temperature using the thulium fiber laser (TFL). In addition, we aimed to identify the differences between the Ho: YAG laser and TFL by direct comparison of the same power settings.

Material and methods: All measurements were performed with a fluid volume fixed at 10 ml and an outflow rate at 10 ml/min. The laser was fired continuously for 30 seconds with total power settings of 10 W, 20 W, 40 W, and 60 W with different power settings (energy × frequency) and various pulse combinations using TFL and Ho: YAG laser (Quanta System, Samarate, Italy).

Results: Higher temperatures were recorded when the power was increased from 10 W, 20 W, 40 W, to 60 W. The temperature exceeded the threshold of 43°C when power settings of ≥40 W were applied regardless of frequency (15-120 Hz) and energy (0.5-4 J). Similar temperature increase patterns were reported with different peak power settings. No major differences were found when the same power settings were applied using TFL and Ho: YAG lasers.

Conclusions: Based on our results temperatures >43°C were recorded for power settings ≥40 W after continuous laser firing of 30 seconds using TFL. Modifying the frequency and energy settings, as well as firing with Ho:YAG laser under the same power setting did not affect the patterns of temperature increase. Generally, the TFL shows more regular thermal behavior in comparison with the Ho:YAG laser.