Effect of Low-Level Laser on Bone Defects Treated with Bovine or Autogenous Bone Grafts:In VivoStudy in Rat Calvaria

Abstract

Objective.The purpose of this study was to histologically evaluate the effect of low-level laser (LLL) on the healing of critical size defects (CSD) in rat calvaria, filled with autogenous or inorganic bovine bone grafts.Methods.Sixty rats were divided into 6 groups(n=10): C (control—filled with blood clot), LLL (low-level laser—GaAlAs,λ780 nm, 100 mW, 210 J/cm2,Φ0.05 cm2; 6 J/point), AB (autogenous bone), ABL (autogenous bone + low-level laser), OB (inorganic bovine bone), and OBL (inorganic bovine bone + LLL).Material and Methods.The animals were killed after 30 days. Histological and histometric analyses were performed by light microscopy.Results.The groups irradiated with laser, LLL (47.67% ± 8.66%), ABL (39.15% ± 16.72%), and OBL (48.57% ± 28.22%), presented greater area of new bone formation than groups C (9.96% ± 4.50%), AB (30.98% ± 16.59%), and OB (11.36% ± 7.89%), which were not irradiated. Moreover, they were significantly better than group C (Kruskal-Wallis test followed by Dunn test,P<0.05).Conclusion.The laser accelerated the healing of bone defects and the resorption of particles of the graft material.