抄録
It is well known that bone tissues are affected by mechanical stimuli, and that osteocytes could be the key
to understanding the mechanisms of bone metabolism under mechanical stress. Low-power laser irradiation
stimulates wound healing in tissues, and we hypothesized that low-power laser irradiation, which is like
mechanical stimulation, can stimulate bone metabolism. The purpose of this study was to test whether lowpower
laser irradiation influences bone tissue. We used a carbon dioxide (CO2) laser, which is frequently used
in dental clinical situations, to examine the effects of low-power laser irradiation on osteocyte functions using
primary osteocyte-like cells.
Osteocyte-like cells were isolated from rat calvariae with enzyme digestion, and the cells received CO2
laser irradiation at doses of 0, 0.5, 1, and 2 W for 10 sec. Osteocyte-like cells isolated from calvariae exhibited
dendritic processes and expressed sclerostin and dentin matrix protein 1 (Dmp-1), which are characteristic of
osteocytes.
CO2 laser irradiation dose-dependently decreased sclerostin mRNA expression and increased Dmp-1 mRNA
expression. Furthermore, these effects were caused directly by laser irradiation without thermal damage.
These results suggest that low-power CO2 laser irradiation influences bone metabolism via osteocytes, and we
demonstrated the possibility of low-power CO2 laser irradiation for bone regeneration therapy.
