Purpose: To evaluate the effect of low-energy level laser irradiation on the proliferation of a culture of human osteoblasts, applying a method already standardized and tested. Materials and Methods: The cell line (NHOst) cultures were distributed into two groups of wells: the experimental wells, containing cells in the proliferative phase, incubated for 48 h, then irradiated with laser photon LASE (As-Ga-Al) for 19 min. Further incubation previous to the cell proliferation test was carried out for 24, 48, 72, 96, 120, and 148 h. In the control group, 48 wells cultured with human osteoblasts were evenly distributed into 3 subgroups termed low (5% culture medium), medium (10% culture medium) and high (15% culture medium). The cell morphology was characterized by immunohistochemistry and the rate of cell proliferation was measured by the XTT test (Roche). Results: After the incubation periods, the difference of the experimental group vs controls was always statistically significant. Conclusion: Normal human osteoblast cells (NHOst) are sensitive to low-level laser irradiation, which increases bone remodeling in a way that could be clinically applied to accelerate orthodontic movement and enhance bone neoformation in the field of periodontal surgery.

Keywords: osteoblasts, low-intensity laser, orthodontic movement, bone remodeling