Numerical Analysis of Laser Thermal Ablation for Gingival and Peri-Implant Inflammation Using Various Laser Irradiation Angles

Because of tooth decay and loss, many people use dental implants as tooth replacements. However, careless management can trigger an inflammatory reaction to an implant. Recently, various studies have been conducted on the sterilization and purification of implant surfaces using diodes, Er:YAG lasers, and CO₂ lasers. In this study, the therapeutic effect of photothermal therapy, a laser treatment method for peri-implantitis, was analyzed through numerical analysis based on heat-transfer theory. The numerical simulation conditions included laser power values in the range of 0.0–4.0 W, laser irradiation angles ranging from 15° to 40°, and laser irradiation durations of 100–500 s. In addition, the Arrhenius damage integral was used to quantitatively verify the therapeutic effects of the photothermal therapy. An analysis of the results confirmed that the Arrhenius thermal damage ratio and normal tissue Arrhenius thermal damage ratio decreased as the laser irradiation angle increased. However, for the same normal tissue Arrhenius thermal damage ratio, the effective laser intensity increased with the laser angle. Finally, the effectiveness of photothermal therapy for peri-implantitis under various conditions was confirmed. These results are expected to optimize the clinical treatment of peri-implantitis in the future.