Effect of Er, Cr: YSGG laser irradiation on Enterococcus faecalis in infected root canals.
OBJECTIVE
The purpose of this study was to investigate the eradication of Enterococcus faecalis by high-power settings of Er, Cr:YSGG laser irradiation in root canals of extracted teeth.


BACKGROUND
The bacteria entering the root canal system invade dentinal tubules, resulting in persistent infections in root canals due to limited penetration of irrigation solutions into the dentinal tubules. The antibacterial effects of different lasers have been investigated in previous studies.


METHODS
Sixty newly extracted maxillary central incisors were enlarged chemomechanically and sterilized after removal of the smear layer. Root canals were inoculated with E. faecalis, and bacteria were incubated in root canals for 48 h. Samples were randomly divided into four groups, each containing 15 teeth. 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 1% sodium hypochlorite for 20 min.


RESULTS
In the laser groups at 2- and 3-W powers, the number of bacteria was reduced 2.4% and 1.53%, respectively, compared with the controls. No significant differences were found between the two laser groups (p > 0.05). The canals irrigated with 1% NaOCl solution demonstrated no bacterial growth.


CONCLUSIONS
According to the results of the present study, 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 NaOCl solution.
Yavari
Hamid Reza
HR
The Department of Endodontics, Tabriz Dental School, Tabriz University of Medical Sciences, Tabriz, Iran.
Rahimi
Saeed
S
Shahi
Shahriar
S
Lotfi
Mehrdad
M
Barhaghi
Mohammed H S
MH
Fatemi
Ali
A
Abdolrahimi
Majid
M
D019551:Dental Disinfectants / Q000627:therapeutic use; D003786:Dental Pulp Cavity / Q000382:microbiology / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D013293:Enterococcus faecalis / Q000528:radiation effects*; D006801:Humans; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D028022:Low-Level Light Therapy; D012388:Root Canal Irrigants / Q000627:therapeutic use; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D014076:Tooth Diseases / Q000628:therapy*
D019551:Dental Disinfectants; D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite