Biological Interactions in Rat Tibial Osteogenesis: Micro-CT, Histomorphometric, and Histological Analyses of...

The study evaluated bone repair in tibial defects of Wistar rats treated with 45S5 bioactive glass, either alone or combined with lyophilized heterologous fibrin biopolymer (HFB) and/or photobiomodulation therapy (PBM). Thirty-five animals were randomly assigned to five groups: control (CG), Bioactive glass (BG), Bioactive glass + HFB (BFG), Bioactive glass + PBM (BPG), and Bioactive glass + HFB + PBM (BFPG). After 42 days, the samples were analyzed by micro-computed tomography, histology (Hematoxylin-Eosin, Masson's Trichrome, and Picrosirius Red), and histomorphometry. Histological and micro-CT findings demonstrated improved defect closure and better matrix organization in the BG and BFG groups. Histomorphometric analysis revealed significant differences among the groups (ANOVA, p < 0.0001), with the BG group showing the highest percentage of new bone formation (40.35 ± 4.14%), significantly higher than the BPG and BFPG groups. The addition of HFB did not impair bone repair and yielded intermediate results, whereas PBM did not demonstrate a positive effect on bone regeneration at the 42-day time point under the parameters used in this study. It can be concluded that bioactive glass, especially when used alone or in combination with heterologous fibrin biopolymer, promoted superior bone regeneration, while its association with photobiomodulation did not demonstrate additional benefit at 42 days.