Effect of low-level laser therapy on the healing of sites grafted with coagulum, deproteinized bovine bone, and biphasic ceramic made of hydroxyapatite and β-tricalcium phosphate. In vivo study in rats.

Abstract

The aim of this study was to evaluate the effect of low-level laser therapy (LLLT) on the healing of biomaterial graft areas (i.e., coagulum, deproteinized bovine bone, and biphasic ceramics comprising hydroxyapatite and β-tricalcium phosphate). Ninety rats were divided into two groups according to laser irradiation use (λ 808 nm, 100 mW, φ ∼600 μm, seven sessions with 28 J of irradiation dose in total): a laser group and a control group. Each of these groups was divided into three subgroups of 15 animals each according to the type of biomaterial used: Coagulum (COA), deproteinized bovine bone (DBB), and hydroxyapatite/β-tricalcium phosphate (HA/βTCP). Biomaterials were inserted into Teflon domes, and these domes were grafted to the lateral aspect of the mandibular branch of the rats. The animals were sacrificed after 30, 60, and 90 days. Scarring patterns were evaluated by microtomography and histometry. The expression levels of BMP2, osteocalcin (OCN), and alkaline phosphatase (ALP) were evaluated by immunohistochemistry. The mRNA expression levels of ALP, BMP2, Jagged1, Osterix, Runx2, and TGFβ1 were determined by RT-qPCR. The animals treated with LLLT exhibited increased mineralized tissues and bone, particularly after 90 days. These increases were associated with increased BMP2, OCN, and ALP protein expression and ALP, BMP2, and Jagged1 mRNA expression. LLLT improved the osteoconductive potential of DBB and HA/βTCP grafts and bone formation in ungrafted areas. Lasers Surg. Med. © 2018 Wiley Periodicals, Inc.