Osteogenic potential of bovine bone graft in combination with laser photobiomodulation: an ex-vivo assessment in Wistar rats by cross-linked studies based on synchrotron microtomography and histology

Background: Alveolar bone defects are usually the main concern when planning implant treatments for appropriate oral rehabilitation of patients. To improve local conditions and achieve implant treatments, there are several methods used for increasing bone volume. among which One of the most successful, versatile, and effective is considered guided bone regeneration. The aim of this demonstrative study was to propose an innovative analysis protocol for the evaluation of the effect of photobiomodulation on bone regeneration process, using rat calvarial defects of 5 mm in diameter, filled with xenograft, covered with collagen membrane, and then exposed to laser radiation. Methods: The animals were sacrificed at different points in time (i.e., after 14, 21, and 30 days). Samples of identical dimensions were harvested in order to compare the results obtained after different periods of healing. The analysis was performed by cross-linkinging the information obtained using histology and high-resolution synchrotron-based tomography on the same samples. A comparison has been made with both negative control (NC) groups (with a bone defect which was left for spontaneous healing), and positive control (PC) groups (in which the bone defects were filled with xenografts and collagen membrane without receiving laser treatment). Results: We demonstrated that using photobiomodulation provides a better healing effect than when receiving only the support of the biomaterial. This effect has been evident for short times treatments, i.e. during the first 14 days after surgery. Conclusion: The proposed analysis protocol has been effective in detecting the presence of higher quantities of bone volumes under remodeling after photobiomodulation with respect to the exclusive bone regeneration guided by the xenograft.