The Effect of Low-Level Laser Therapy in Combination with Leukocyte- and Platelet- Rich Fibrin on Bone Regeneration in Rabbits’ Calvarial Defects: Histologic and Histomorphometric Studies

OBJECTIVES: Bone regeneration is a desired treatment outcome in implant dentistry. The primary goal of the current investigation was to assess the joint effect of low-level laser therapy (LLLT) and leukocyte- and platelet-rich fibrin (PRF) on new bone formation. MATERIALS AND METHODS: During this experiment study, forty bone defects (8 mm in diameter) were generated in the calvaria of ten New-Zealand white rabbits. defects were filled with autogenous bone defined as the control group, autogenous bone with leukocyte- and PRF (PRF group), autogenous bone and low-level diode laser radiation (LLLT group), and autogenous bone with leukocyte- and PRF and low-level laser radiation (LP group). Laser irradiation was done every second day for 2 weeks after surgery. Five rabbits were randomly selected to be sacrificed on postoperative weeks 4 and 8. On one and two-month post-surgery, histological and histomorphometric parameters including bone formation, fibroblast, and osteoblast were assessed. RESULTS: The histological panel depicted that the ratio of fresh bone formation increased at one-and two-month post- surgery in all treatment groups compared to the control group. The most favorable results were seen in the LP group, followed by the PRF group. Based on the ANOVA test, bone neoformation was statistically significant in the LP group in comparison with the control group (P<0.001). One-month post-surgery, a higher degree of fibroblast was seen in the control group, while the last place was for LP group (118.6 ± 6.9 vs. 24.0 ± 3.2). In the PRF group, the percentage of bone formation was higher than that in the control group (13.2 ± 2.8 vs. 2.0 ± 1.2), but no significant difference when compared to the LP group (13.2 ± 2.8 vs. 19.0 ±.3.8). CONCLUSION: The combined L-PRF and LLLT was more likely to have a positive effect on accelerating bone regeneration and reducing fibrosis.