High-power diode laser in the disinfection in depth of the root canal dentin

Objective. The objective of this study was to evaluate the disinfection degree of dentine caused by the use of diode laser after biomechanical procedures. Study design. Thirty teeth were sectioned and roots were autoclaved and incubated for 4 weeks with a suspension of Enterococcus faecalis. The specimens were randomly divided into 3 groups (n = 10): G1, instrumented with rotary files, irrigated with 0.5% sodium hypochlorite and 17% EDTA-T, and then irradiated by 830-nm diode laser at 3 W; G2, the same procedures as G1 but without laser irradiation; and G3, irrigation with saline solution (control). Dentin samples of each third were collected with carbide burs and aliquots were sowed to count viable cells. Results. The disinfection degree achieved was 100% in G1 and 98.39% in G2, when compared to the control group (G3). Conclusion. Diode laser irradiation provided increased disinfection of the deep radicular dentin in the parameters and samples tested.