Effects of ultrasound on cementoblast metabolism in vitro

Ultrasound (US) has been shown to alter cell/tissue functions. However the effects of US on cementoblasts are not known. The aim of the present study was to evaluate the effect of US exposure on proliferation and metabolism of cementoblast (murine cementoblastic cell line [OCCM-30]) in vitro. Cultured cementoblasts received US exposure (frequency = 1 MHz; pulsed 1:4; spatial-average intensities (I(SA)) = 100, 150 or 400mW/cm(2)) or sham exposure for 15 min per d for 4 d. They were then assayed for calcium content and cell proliferation. Furthermore, expression levels of osteocalcin, bone-sialoprotein, alkaline phosphatase and osteopontin were analyzed by real time polymerase chain reaction. Calcium content was statistically increased (p < 0.05) after US exposure at 100 or 150 mW/cm2. Alkaline phosphatase mRNA levels were (p < 0.05) increased significantly by US stimulation with 150 mW/cm2. These results demonstrate that US affects cementoblasts by regulation of some genes-related protein in vitro and, although more studies are necessary, it may be important to consider in designing in vivo US therapies targeted at the oral cavity.