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.