Effect of laser photobiomodulation associated with a bioceramic cement on the repair of bone tissue in the femur of rats

This study aimed to evaluate in vivo the effect of laser photobiomodulation associated with a repair cement (MTA Repair HP (TM)) on the process of bone repair in the femur of rats, through histological and histomorphometric assays. Forty Wistar albino rats were randomly divided into four groups, with two periods of euthanasia - 15 and 21 days (n = 5 per period). Under general anesthesia, a bone defect was made in the left femur of each animal. In the LS (Laser) group, the defect was irradiated following the parameters: lambda = 808 nm, P = 100 mW, ED = 80 J/cm(2) per point, 22 s per point, E = 2.2 J per point. In the LM (MTA Repair HP (TM) + Laser) group, the defect was filled with MTA Repair HP (TM) and irradiated with laser in the same protocol of the LS group. In the MH (MTA Repair HP (TM)) group, the defect was filled with MTA Repair HP (TM) without irradiation. In the CTR (Control) group, the bone defect received no treatment. At 15 days, the mean index of bone neoformation in the defect area was significantly lower in the CTR group as compared to the MH, LS, and LM groups. At 21 days, the LM group presented significantly greater bone neoformation than the MH group, without significant difference between LS and LM. Laser photobiomodulation therapy is promising as an adjuvant in the bone repair process, especially when associated with the use of biomaterials.