Objective: This investigation was performed to evaluate the possibility of the removal of canine gingival melanin pigmentation with the semiconductor diode (SCD) laser in vivo. Summary Background Data: Recently, a semiconductor laser, which can ablate soft tissue, has been developed. It is already used in dentistry as well as in medicine. Methods: The SCD laser was irradiated on the pigmented area of canine gingival surface with the irradiation output of 3W. The effect of the SCD laser irradiation was evaluated at the two intervals: immediately after irradiation and at 3 weeks following irradiation. In addition, histological examination was performed before irradiation and at the same intervals from the biopsies (4 μm) of unlased and lased areas. Results: The SCD laser was effective in removing melanin pigmentation. In histological examination, neither inflammatory cell nor any tissue damage was observed with hematoxylin-eosin staining. At 3 weeks, there was a continuous healing process with the proliferation of squamous epithelial cells. Conclusions: SCD laser irradiation can be considered an alternative procedure for removal of melanin pigmentation.
