Low level laser therapy does not modulate the outcomes of a highly bioactive glass–ceramic (Biosilicate®) on bone consolidation in rats

Abstract

The main purpose of the present work was to evaluate if low level laser therapy (LLLT) can improve the effects of novel fully-crystallized glass-ceramic (Biosilicate) on bone consolidation in tibial defects of rats. Forty male Wistar rats with tibial bone defects were used. Animals were divided into four groups: group bone defect control (CG); group bone defect filled with Biosilicate (BG); group bone defect filled with Biosilicate, irradiated with LLLT, at 60 J cm(-2) (BG 60) and group bone defect filled with Biosilicate, irradiated with LLLT, at 120 J cm(-2) (BG 120). A low-energy GaAlAs 830 nm, CW, 0.6 mm beam diameter, 100 W cm(-2), 60 and 120 J cm(-2) was used in this study. Laser irradiation was initiated immediately after the surgery procedure and it was performed every 48 h for 14 days. Fourteen days post-surgery, the three-point bending test revealed that the structural stiffness of the groups CG and BG was higher than the values of the groups BG60 and BG120. Morphometric analysis revealed no differences between the control group and the Biosilcate group. Interestingly, the groups treated with Biosilicate and laser (BG 60 and BG120) showed statistically significant lower values of newly formed bone in the area of the defect when compared to negative control (CG) and bone defect group filled with Biosilicate (CB). Our findings suggest that although Biosilicate exerts some osteogenic activity during bone repair, laser therapy is not able to modulate this process.

Characterization andIn VivoBiological Performance of Biosilicate

“…Oliveira et al [27] used 40 male Wistar rats divided into 4 groups: bone defect control group (CG), bone defect filled with Biosilicate group (BG), and bone defect filled with Biosilicate and irradiated with LLLT at 120 J cm(−2) group (BG 120). The size of particle used for Biosilicate was 180–212 micrometers.…”

Low-Level Laser Therapy Induces Differential Expression of Osteogenic Genes During Bone Repair in Rats

“…35,36 The model of bone defects has been used by many authors. [36][37][38] It was found that the dose of the laser used had a positive result on bone metabolism at the site of injury. It is possible to find in the literature a wide range of fluencies and wavelengths of laser irradiation used by different authors on bone healing and fractures.…”

The effects of grapeseed extract and low level laser therapy administration on the liver in experimentally fractured mandible

“…Thus, it was also mentioned that by triggering vascularization and inflammatory response, it facilitates bone matrix production as well (30). However, in certain studies, although the positive effect of LLLT on hard and soft tissue recovery was demonstrated, it was observed that the estimated effect on recovery was not seen or the laser had negative effects (31)(32)(33). In our study, we observed that MDA and CAT levels in the liver of the rats in the groups where mandibular defect + laser were applied both for 7 and 21 days were similar to that of the mandibular defect group (P<0.05).Under certain conditions where free radicals are produced extensively such as inflammation or trauma, endogenous antioxidants could be insufficient.…”