The effect of the association of near infrared laser therapy, bone morphogenetic proteins, and guided bone regeneration on tibial fractures treated with internal rigid fixation: a Raman spectroscopic study

Abstract

Fractures have different etiology and treatment and may be associated or not to bone losses. Laser light has been shown to improve bone healing. We aimed to assess, through Raman spectroscopy, the level of CHA (∼958 cm−1) on complete fractures animals treated with IRF treated or not with Low Level Laser Therapy—LLLT and associated or not to BMPs and GBR. Complete tibial fractures were created on 15 animals that were divided into five groups. LLLT (Laser Unit, Kondortech, São Carlos, SP, Brazil, λ790 nm, 4 J/cm2/point, 40 mW, ϕ ∼ 0.5 cm2, 16 J/cm2 session) started immediately after surgery and repeated at 48 h interval (2 weeks). Animal death occurred after 30 days. Raman spectroscopy was performed at the surface of the fracture. Our results showed significant differences between the groups IRF + BL /IRF_NBL (p = 0.05); between all experimental groups and untreated bone; bone/IRF + BL; IRF + BL + Bio + GBR; IRF + BL + LLLT; IRF + BL + Bio + GBR + LLLT; IRF_NBL (p < 0.001, all); IRF_NBL/IRF + BL + LLLT (p = 0.03); IRF_NBL/IRF + BL + Bio + GBR + LLLT (p = 0.02); IRF + BL/IRF + BL + LLLT (p = 0.04); IRF + BL/IRF + BL + Bio + GBR + LLLT (p = 0.002); IRF + BL + Bio + GBR/IRF + BL + Bio + GBR + LLLT (p = 0.05). It is concluded that the use of NIR LLLT associated to BMPs and GBR was effective in improving bone healing on fractured bones due to increased levels of CHA.