Effect of low-level laser therapy and calcitonin on bone repair in castrated rats: a densitometric study.

OBJECTIVE To investigate the healing of bone defects in male rats treated with salmon calcitonin, low-level laser therapy (LLLT), or both. BACKGROUND Healing of bone defects still represents a challenge to health professionals in several areas. In this article, the effect of calcitonin in combination with LLLT on bone repair was studied. Densitometry was used as a valuable tool for the measurement of bone regeneration. METHODS Sixty male Wistar rats underwent bilateral castration surgery before the creation of a surgical bone defect. The animals were randomly divided into four groups: control, treated with calcitonin (Ca), treated with LLLT (La), and treated with calcitonin and LLLT (CaLa). Groups Ca and CaLa received 2 IU/kg of synthetic salmon calcitonin intramuscularly three times a week. Groups La and CaLa received laser therapy using a gallium-aluminum-arsenide laser (10 mW, 20 J/cm(2), wavelength 830 nm). Control animals were submitted to sham irradiation. The animals were sacrificed 7, 14, and 21 days after surgery, and bone defects were analyzed using densitometry. RESULTS The CaLa group had a higher degree of bone regeneration 14 and 21 days after surgery. CONCLUSIONS The La and CaLa had significantly higher bone mineral density than the control and Ca groups.