This laboratory study investigated how a 445 nm diode laser (Eltech K-Laser Srl, Treviso, Italy) affects the surfaces of dental implants under various power levels and irradiation methods. Fifteen new Straumann implants (Basel, Switzerland) were examined for surface changes. Each implant was divided into two regions: anterior and posterior. The anterior coronal portion was irradiated with the laser fiber positioned 1 mm away, whereas the anterior apical portion was treated with the fiber in direct contact. Posterior regions remained unexposed and served as controls. The laser was applied in two 30-second cycles, separated by a one-minute rest. Three settings were tested: 0.5 W pulsed (T-on 25 ms; T-off 25 ms), 2 W continuous, and 3 W continuous. Surface modifications were assessed using scanning electron microscopy (SEM). Results showed that the 0.5 W pulsed laser at a 1 mm distance caused no detectable changes. Continuous irradiation at 2 W and 3 W led to visible surface damage at the same distance, and direct fiber contact further intensified alterations. These findings suggest that using a 0.5 W pulsed laser with a fiber kept 1 mm from the implant may provide a safe approach for peri-implantitis therapy, avoiding damage to implant surfaces.
