The antibacterial efficacy of Er, Cr

Abstract

Bacteria entering the root canal system invade dentinal tubules, which may result in persistent infections in root canals due to limited penetration of irrigation solutions into these tubules. Furthermore, bacteria such as Enterococcus faecalis have the ability to produce intra- and extraradicular biofilms that make their elimination difficult. Due to the adjustable penetration depth of the laser irradiation, lasers can result in better access to complex regions of the root canal system. Erbium lasers such Er, Cr:YSGG laser with water-absorption wavelength of 2,780 nm is suitable to remove dental hard tissues. This study aimed at comparing the effect the Er, Cr:YSGG laser with that of %2 chlorhexidine solution in reducing the number of E. faecalis in infected root canals. Materials & Methods: Root canals of sixty extracted maxillary incisors were inoculated with E. faecalis, and bacteria were incubated in root canals for 24 h. Samples were randomized into four equal groups. One group was considered as control with no intervention. Two groups were irradiated with 2- and 3-W output powers of Er, Cr:YSGG laser for 16 s. In the last group, the canals were irrigated with 2% chlorhexidine solution. Results: In the laser groups at 2- and 3-W powers, the number of bacteria was reduced to 4.69% and 2.91%, respectively, compared with the controls. No significant differences were found between the two laser groups. In the 2% chlorhexidine solution group, the number of bacteria was reduced to 0.85%, compared with the controls. The number of bacteria in the 2% chlorhexidine solution group decreased significantly more than that in the laser groups. Conclusions: Based on our results, 2- and 3-W powers of Er, Cr:YSGG laser have antibacterial effects on E. faecalis in root canals of infected teeth; however, the effect is less remarkable than that of 2% chlorhexidine solution.