Abstract
Laser treatment is widely used for dental treatment in general practice. Recently, it has been demonstrated that low reactive level laser therapy （LLLT） can induce bone formation, and LLLT has been expected to be used for bone regeneration therapy. However, some reports have demonstrated that LLLT stimulates bone resorption as well as bone formation. Thus, LLLT is a double-edged sword in bone regeneration therapy. In order for LLLT to be used effectively for bone regeneration therapy, it is necessary to clarify the mechanism of laser action on bone metabolism. In this review, we focus on the action of laser on bone metabolism and consider the mechanism of both bone formation and resorption based on bone immunology, with reference to the literature.
