低出力レーザー照射による骨組織形成促進作用に関する実験的研究

と く に照射期間および照射時間による影響について

抄録

Many low-powewr laser apparatus have developed and efficiencies of this apparatus on the treatment of hypersensitivity of dentin, stomatitis and tempora-mandibular joint syndrome have been reported. In addition, several reports indicated that the appliation of lowpower laser improved the wound healing, repair of bone fracture and remodelling of defected bone. However, there was no reports which quantitatively analysed the effect of low power laser. The purpose of this study is to investigate the effect of low-power laser irradiation on bone remodelling using rat calvaria with an artificially formed defect.
He-Ne laser with 632.8nm, 6mW and semiconductive laser with 830nm, 30mW were used as laser apparatus. An artificial bone defect with a diameter of 3mm were prepared by a low speed dental engine fixed in a drill in the center of each calvaria. The laser irradiation was applied to bone defect in right calvaria as an experimental site for 10 minutes once a day and this procedure was carried out up to 3 days, 1, 2, 3, 4, 5 or 6 weeks, respectivery. Bone defect in left calvaria used as a control side was not given laser irradiation. Laser irradiation was also applied to bone deffect in only right calvaria for 2.5, 5, 10, 15, 20, 30, 40, 50 or 60 minutes per a day up to one week.
Results obtained were as follows:
1. New bone formation was enbanced with He-Ne laser and Semiconductive laser irradiation from 1 Week to 4 weeks, and there was a significant differrence between irradiation groups and the control group on the amount of new bone.
2. No efffect on new bone formation was observed in non-irradiated site.
3. The Effect of He-Ne laser irradiation time on new bone formation was observed over 5 minutes irradiation per day, and over 10 minutes per day there was a significant difference between the irradiation group and the control group.