Effect of Photobiomodulation Therapy Associated With Biphasic Phosphate Calcium on Bone Repair: A Histomorphometric Study in Rats

Abstract

Introduction: This study aimed to investigate the effects of photobiomodulation (PBM) therapy associated with biphasic calcium phosphate on calvaria critical defects in rats. Methods: Forty-eight (90 days old) adult male rats (Rattus norvegicus, Albinus variation, Wistar) received critical defects of 5 mm in diameter, which were made on their skull, and they were randomly assigned into the following groups: C-blood clot, B-biphasic calcium phosphate, L-photobiomodulation therapy, and B + L-biphasic calcium phosphate + photobiomodulation therapy. A low-level a gallium aluminum arsenide (GaAlAs) laser was applied in a single dose during surgery, in a wavelength of 660 nm and total energy density of 45 J/cm2. On 30th and 60th days, the animals from each group were euthanized. Histological and histomorphometric analyses were performed. Results: In 30 days, almost all specimens (C, L, B and B + L) showed bone neoformation areas in regions near the borders of the surgical defect. In 60 days, in many specimens (C, L, B, B + L), it was possible to see a narrow neoformed bone structure along almost the whole extension of the surgical defect, though it was thinner than the original calvary bone. Data were recorded as mean ± standard deviation, and after normality was tested, a suitable statistical test was applied (α = 5%). On day 60, there was a statistically significant difference when comparing the proportion of neoformation area between group L (0.52% ± 0.13) and group B + L (0.20% ± 0.08). Group L showed a difference compared with all the groups when we compared the remaining distance between the edges of neoformed bone (C × L, P = 0.0431; B × L, P = 0.0386; L × B + L, P = 0.0352), demonstrating a great defect closure. Conclusion: Our findings suggest that although biphasic calcium phosphate exerts some osteogenic activity during bone repair, PBM therapy is not able to modulate this process.

Photobiomodulation Therapy Improves Repair of Bone Defects Filled by Inorganic Bone Matrix and Fibrin Heterologous Biopolymer

“…At 42 days, the G1, G2 and G3 groups showed immunostaining for OCN in the newly formed bone lamellae, which would be expected in all groups, as they go through the process of bone maturation [87][88][89]. In the OCN and TRAP analysis, a higher immunostaining pattern was presented in the G1 group when compared to the others, which would be justified by the fact that the G1 group is still in a less mature bone formation process than the other groups [90][91][92].…”