The effect of low power laser (diode laser) irradiation on the mineralizationand alkaline phosphatase activity in the tooth germ was examined.Mandibular first molarsfrom 17-day-old mouse embryos were cultured with or without low power laser irradiation (the irradiation time were 0, 1, 3 or 5 minutes per day). The calcium content and alkalinephosphatase activity in the tooth germ increased gradually from 0 to 7 days in culture, theincrease of calcium content being preceded by that of alkaline phosphatase activity. The irradiation by low power laser (5 minutes) increased the alkaline phosphatase activity in thetooth germ cultured for 3 days, without affecting the calcium content. There was no increaseof alkaline phosphatase activity in the tooth germ cultured and irradiated with low powerlaser for 7 days. However the irradiation by low power laser (5 minutes) increased calciumcontent in the tooth germ.
These results suggest that low power laser irradiation may accelerate the mineralizationstage of the tooth germ. For evaluating the action on mineralization in the tooth germ, irradiation of 5 minutes per day was optimal. (J. Jpn. Soc. Laser Dent. 4: 27-31, 1993 Reprint requests to Dr. Arakawa)
