Figure 2
LPLI increased the osteogenic differentiation of hPDL cells. hPDL cells were divided into the following four groups: negative control, which was cultured in BK medium; OIM-0, which was cultured in OIM only; OIM-2, which was cultured in OIM and treated with LPLI at 2 J⋅cm−2; and OIM-4, which was cultured in OIM and treated with LPLI at 4 J⋅cm−2. (a) The ALP activity of the hPDL cells was analyzed on days 3 and 5, as described in the section on ‘Materials and methods’ (n=6). (b) hPDL cells were cultured for 7, 10 and 14 days. After fixation, the cells were stained with Alizarin Red S (n=6). (c) Relative quantification of Alizarin Red S based on the staining shown in a. The data are shown as the mean±s.d., and the levels of statistical significance are indicated as follows: *P<0.05 and **P<0.01 relative to the OIM-0 group; ##P<0.05 relative to the OIM-2 group. ALP, alkaline phosphatase; hPDL, human periodontal ligament; LDH, lactate dehydrogenase; LPLI, low-power laser irradiation; OIM, osteo-induction medium.
