Skuteczność bakteriobójcza promieniowania lasera diodowego względem Enterococcus faecalis w porównaniu z irygacją podchlorynem sodu

Abstract

Background. Microorganisms surviving in the root canal system despite the chemomechanical preparation are the main reason for reinfection and endodontic treatment failure. The introduction of laser-assisted endodontics resulted in higher success rates and less recurrent infections.Objectives. To compare the antibacterial action of diode laser irradiation (CV – 1500 W, IMP – 3000 W), photoactivated disinfection (PAD), and 5.25% sodium hypochlorite (NaOCl) on Enterococcus faecalis in an infected tooth model.Material and Methods. Fifty freshly extracted bovine teeth with single canals were prepared to apical size 45° ISO, autoclaved and contaminated with Enterococcus faecalis. After a 48-hour incubation the specimens were randomly divided into four treatment groups and one control group (n = 10): Group 1 was irradiated with 1500 mW (continuous wave diode laser irradiation); Group 2 was irradiated with 3000 mW (impulse diode laser irradiation, 300 ms – pulse, 300 ms – pause); Group 3 was subjected to photo-activated disinfection and Group 4 was irrigated with a 5.25% NaOCl solution for 15 min. Group 5 was rinsed with saline solution (control). After treatment, the dentin samples were collected and the number of surviving bacteria was determined by classical quantitative microbiologic evaluation.Results. The differences in the mean number of the colony forming units (CFU/mg) between all the groups analyzed were statistically significant (p < 0.001). The highest number of microorganisms was observed in the control group (52.7 x 103 CFU/mg). Both diode laser applications resulted in a significant reduction in the number of E. faecalis cells: G1 – 1.4 x 103 CFU/mg, G2 – 4.2 x 103 CFU/mg, whereas in the group subjected to photo-activated disinfection the extent of reduction was significantly less (G3 – 42.8 x 103 CFU/mg).Conclusion. The present study demonstrates that CW and pulse diode laser applications are both suitable for root canal disinfection, but do not eradicate all bacteria.