Thermal Transfer on Splinted Implants During Diode Laser Irradiation In Vitro

Objective: Laser irradiation is being used for treatment of peri-implantitis. Therefore, this study aimed to assess the heat transfer from laser irradiation on an implant-supported, metal–ceramic fixed prosthesis in vitro. Materials and methods: Two titanium implants were placed in artificial type I bone, and after abutment connection, a bridge was fabricated and cemented. A peri-implant 3-wall defect was created around one of the implants. Thermocouples were placed at coronal (T1/T2) and apical (T3/T4) positions of both implants, and the T5 thermocouple was placed in the pontic. An identical setup was created in the type IV artificial bone. Diode laser irradiation (2 W, noninitiated tips, 320-μm fiber, and noncontact) was performed for 60 sec on each experimental model. This experiment was performed separately with 810- and 980-nm lasers for pulsed and continuous modes. ΔT based on the baseline was recorded during irradiation. Statistical analysis was performed with repeated analysis of variance. Results: Across all experimental models, the recorded ΔT (°) values in T2, T4, and T5 at 10, 30, and 60 sec were significantly less than 10°C (p < 0.001) for both types of bones. For both types of bones, there was a statistically significant ΔT greater than 10°C (p < 0.001) for continuous and pulsed 980-nm irradiation and continuous 810-nm diode laser irradiation after 60 sec. For both 810- and 980-nm lasers, there was a statistically significant ΔT greater than 10°C (p < 0.001) for type I and IV bones under irradiation and only for the type I bone model under pulsed irradiation after 60 sec. Conclusions: Within the limitations of this study, 810- and 980-nm lasers on splinted implants placed in vitro may increase the temperature on adjacent splinted implants due to material conductivity and splinting. Clinicians are advised to keep the temperature lower than the critical threshold following recommended power settings to avoid excessive heat and control complications due to overheating.