Thermal Effects of Diode Laser-Irradiation on Titanium Implants in Different Room Temperatures In Vitro.

Abstract

Objective: The aim of this study was to determine the thermal effects of diode laser irradiation on titanium implants. Methods: An implant (3.5 × 11 mm) was placed into a bovine bone block. A three-wall intrabony defect was created to simulate peri-implant defect. Two thermocouples were secured to the apical and coronal surfaces to measure temperature changes (ΔT) during irradiation. The block was placed in a 37°C water bath and at room temperature (21°C). The defect was irradiated with different diode lasers (fiber 300 μm), while the coronal part of the implant was slightly emerging from the water. While the laser tip was positioned parallel to the implant, the defect was irradiated for 30 sec at 2 W in continuous and pulsed mode. Twenty laser irradiations were performed for each laser wavelength for assessment of ΔT. The linear mixed model was used for comparative statistics. Results: The 980 nm pulsed laser resulted in the highest ΔT (°C) at the coronal (22.45 ± 2.1/14.15 ± 0.13) and apical level (5.4 ± 0.56/3.56 ± 0.35) when this laser was used in both room temperature and water bath conditions, respectively. Similarly, highest ΔT (p < 0.0001) for the 810 nm was 14.3 ± 1.6/12.51 ± 0.63 and apical 3.42 ± 0.52/2.58 ± 0.25, for the 970 nm was 13 ± 1.4/9.93 ± 0.47 and apical 2.89 ± 0.19/2.01 ± 0.19 compared to the 940 nm laser coronally 10.1 ± 0.6/9.19 ± 0.35 and apically 1.67 ± 0.34/1.80 ± 0.17. The coronal part of the implant surpassed the critical threshold of 10°C when irradiated with each of the lasers in the room temperature conditions. Conclusions: Within the limitations of the study, the 940 nm laser seems to control better the risks of overheating during implant irradiation.