Disinfection degree in depth by diode laser irradiation – Intracanal study

Objectives: the laser irradiation presents properties that may improve the treatment success rates, reducing the microbial contamination. The aim of this study is evaluate the disinfection degree in depth caused by diode laser irradiation after chemomechanical procedures in vitro. Methods: thirty extracted dental roots were sterilized by autoclave, inoculated by strain of Enterococcus faecalis during 4 weeks, and then randomly divided in 3 groups. Group 1: 10 specimens were instrumented by rotary files K3 with 0.5 % sodium hypochlorite and urea peroxide (Endo PTC cream). At the end irrigation by 17 % EDTA-T was performed. The specimens were irradiated intracanal by diode laser 830 nm wavelength 3 W during 5 seconds, four times. Group 2: same procedures of group 1 without laser irradiation. Group 3: irrigation by saline solution. Samples of dentin were obtained with carbide burs from inner canal walls of each third. The samples were immersed in 1 mL of peptonic water, and then aliquots were sowed to count viable cells in mEnterococcus agar. Results: the disinfection degree achieved was 100 % in group 1, 98,39 % in group 2 both compared with group 3. The Kruskal-Wallis statistical analysis with Dunn method of comparison shows better results in group with diode laser irradiation (p<0.05), followed by group 2 and 3. Conclusions: irradiation by diode laser in that samples and parameters achieved disinfection improvement in root dentin depth.