Evaluation of the Effects of Photobiomodulation on Biomechanical Properties and Hounsfield Unit of Partial Osteotomy Healing in an Experimental Rat Model of Type I Diabetes and Osteoporosis

Background: Pulsed wave (PW) lasers exhibit biostimulatory effects on fractures in healthy and diabetic animals.

Objective: This study aims to assess the effects of photobiomodulation on bone strength and Hounsfield unit (HU) for repair of a bone defect in an experimental rat model of type I diabetes mellitus (TIDM) and osteoporosis (OP).

Methods: We divided 30 female rats into six groups of n = 5 per group: (1) ovariectomy (OVX) control, (2) OVX + PW laser and no TIDM, (3) OVX control + TIDM, (4) OVX + TIDM + PW laser, (5) OVX + TIDM + alendronate, and (6) OVX + TIDM + PW laser + alendronate. TIDM was induced in rats by streptozotocin (STZ). A partial osteotomy was made in the right tibia of each rat. We used an infrared laser (890 nm, 80 Hz, 1.5 J/cm²) 3 times per week. At 30 days after surgery, the callus areas within the rats' tibias were submitted to computed tomography scanning followed by the three-point bending test.

Results: The PW laser + alendronate group had significantly increased HU and biomechanical properties of repairing bone defect in STZ + OVX rats compared with the control groups.

Conclusions: Combined treatment of PW laser and alendronate significantly enhanced bone repair in an experimental model rat of TIDM and OP.