Journal of the Korean Academy of Pediatric Dentistry 2013;40(4):241-246.
Published online November 30, 2013.
Enhancement of Erythrosine Photodynamic Therapy against Streptococcus mutans by Chlorhexidine
Jongcheol Park1, Howon Park1, Siyoung Lee2
1Department of Pediatric Dentistry, College of Dentistry, Gangneung-Wonju National University
2Department of Microbiology and Immunology, Oral Science Research Center, College of Dentistry, Gangneung-Wonju National University 
Correspondence:  Howon Park,  Tel: +82-33-640-2464, Fax: +82-33-640-3113, Email:
Received: 12 April 2013   • Accepted: 7 September 2013
The purpose of this study was to investigate the synergistic effects of erythrosine sensitized with a conventional halogen curing unit and sub-minimal bactericidal concentration(sub-MBC) of chorhexidine on bacterial viability of Streptococcus mutans in planktonic state. Sub-minimal bactericidal concentration of chlorhexidine was added into wells containing bacteria and erythrosine. The range of concentrations tested for chorhexidine was from 0.0000001% to 0.001%. The irradiation of the bacterial suspensions was performed for 15 sec with a conventional halogen curing unit light. In another set of experiment, the effects of 0.001% chlorhexidine were observed by adding chlorhexidine into wells containing the sub-minimal bactericidal concentration of erythrosine. At the concetration of 0.001% chlorhexidine, there were no antibacterial effects in the absence of erythrosine PDT(p < 0.05). At the concentraton of 1 μM erythrosine, there was no photodynamic therapy effect in the absence of chlorhexidine(p < 0.05). But in the presence of sub-minimal bactericidal concentration of erythrosine with light exposure, the addition of 0.001% chlorhexidine increased the bactericidal rate(p < 0.05). A combination of erythrosine PDT with sub-MBC chlorhexidine resulted in a significant reduction in bacterial counts when compared to the case with the absence of chlorhexidine.
Key Words: Photodynamic therapy, Erythrosine, Halogen, Streptococcus mutans, Chlorhexidine

Editorial Office
Seoul National University, Dental Hospital, B1-166 101, Daehak-ro, Jongno-gu, Seoul 03080, Republic of Korea
Tel: +82-70-4145-8875    Fax: +82-2-745-8875    E-mail:                

Copyright © 2022 by Korean Academy of Pediatric Dentistry.

Developed in M2PI

Close layer
prev next