Purpose: Successful endodontic therapy is based mainly upon effective mechanical instrumentation and disinfection of root canals. This study compares the antibacterial effect of Erbium, chromium: yttrium-scandium-gallium-garnet (Er, Cr:YSGG) laser 2780nm wavelength, diode laser 940nm wavelength and sodium hypochlorite (NaOCl) 5.25% solution on Enterococcus faecalis (E. faecalis) biofilm.
Materials and methods: A total of 50 extracted human permanent maxillary central incisor teeth were prepared to size X4 Protaper Next and contaminated with E. Faecalis for biofilm formation. After ten days of incubation and based on the method of disinfection of the root canals, the specimens were randomly grouped into; group A (n=15), which was irradiated by ER, Cr: YSGG laser 2780nm wavelength; group B (n=15), which was irradiated with a diode laser 940 nm wavelength; group C (n=15), which was rinsed with 5.25% NaOCl solution. Three teeth were used to confirm the biofilms formation by scanning electron microscope (SEM) and two teeth served as negative control. Intracanal bacteria sampling was performed under complete aseptic conditions before and after disinfection. The specimens were cultured to enumerate the colony forming units (CFUs) count.
Results: Although group C (5.25% NaOCl solution) showed a more disinfection than both laser systems, there was no significant difference between all groups (P> 0.05).
Conclusion: Both ER, Cr: YSGG laser 2780nm wavelength and diode laser 940nm wavelength have nearly similar antibacterial efficacy on E. faecalis compared with NaOCl 5.25% solution. The use of laser for root canal disinfection may be advantageous considering several unfavorable actions of NaOCl.