Benefits of Using Low-level Laser Therapy in the Rapid Maxillary Expansion: A Systematic Review

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

Biomaterials are used extensively in graft procedures to correct bone defects, interacting with the body without causing adverse reactions. The aim of this pre-clinical study was to analyze the effects of photobiomodulation therapy (PBM) with the use of a low-level laser in the repair process of bone defects filled with inorganic matrix (IM) associated with heterologous fibrin biopolymer (FB). A circular osteotomy of 4 mm in the left tibia was performed in 30 Wistar male adult rats who were randomly divided into three groups: G1 = IM + PBM, G2 = IM + FB and G3 = IM + FB + PBM. PBM was applied at the time of the experimental surgery and three times a week, on alternate days, until euthanasia, with 830 nm wavelength, in two points of the operated site. Five animals from each group were euthanized 14 and 42 days after surgery. In the histomorphometric analysis, the percentage of neoformed bone tissue in G3 (28.4% ± 2.3%) was higher in relation to G1 (24.1% ± 2.91%) and G2 (22.2% ± 3.11%) at 14 days and at 42 days, the percentage in G3 (35.1% ± 2.55%) was also higher in relation to G1 (30.1% ± 2.9%) and G2 (31.8% ± 3.12%). In the analysis of the birefringence of collagen fibers, G3 showed a predominance of birefringence between greenish-yellow in the neoformed bone tissue after 42 days, differing from the other groups with a greater presence of red-orange fibers. Immunohistochemically, in all experimental groups, it was possible to observe immunostaining for osteocalcin (OCN) near the bone surface of the margins of the surgical defect and tartrate-resistant acid phosphatase (TRAP) bordering the newly formed bone tissue. Therefore, laser photobiomodulation therapy contributed to improving the bone repair process in tibial defects filled with bovine biomaterial associated with fibrin biopolymer derived from snake venom.

Photobiomodulation increases uprighting tooth movement and modulates IL-1β expression during orthodontically bone remodeling

This study investigated the effects of photobiomodulation (PBM) in acceleration of orthodontic movement of inferior molar uprighting movement. Thirty-four individuals, with indication of molar uprighting movement for oral rehabilitation, were randomly divided in two groups: verticalization + PBM (808 nm, 100 mW, 1 J per point, 10 points and 25 J/cm2 ) or verticalization + PBM simulation. Elastomeric chain ligatures were changed every 30 days for 3 months. FBM was performed immediately, 24 h, 72 h, 1 and 2 months after activation. The primary outcome was the amount of uprighting movement. Secondary outcomes were pain, amount of medication, OHIP-14 questionnaire, and cytokine IL-1β. PBM group increase uprighting movement when compared to control after 3 months and modulate IL-1β expression. For pain control, the amount of medication and OHIP-14 no difference were found. This study suggests that PBM accelerates tooth movement during molar uprighting, due to modulation of IL-1β during bone remodeling.