[Inhibition effect of methylene blue on the acids production of Streptococcus mutans].
OBJECTIVE
To study the effect of methylene blue on the growth and acid production of Streptococcus mutans, and the effect of methylene blue on acid production metabolism in plaque glycolysis model (i-PGM) in vitro, and investigate the practicability of methylene blue as a new kind of dental caries prevention agent.


METHODS
Nephelometer method was used to measure OD value of Streptococcus mutans culture fluid in the different incubation conditions. The kinds and quantities of acid produced by Streptococcus mutans in the different incubation conditions were measured with gas chromatography. pH values of glycolysis buffer media of i-PGM in the different treatment conditions were measured by ORION electrode.


RESULTS
(1) The OD value of Streptococcus mutans treated by methylene blue was lower than that by normal saline, and there was significant statistical difference between them. (2) The kinds of acid in three different culture fluid were same, but the total quantities of acid were significantly different among three different culture fluid, in which the total quantities of acid of culture fluids treated by glucose was the greatest, and treated by methylene blue was the lest. (3) The pH value of i-PGM treated by methylene blue was significantly different compared with negative control group, but was not significantly different compared with positive control group.


CONCLUSIONS
Methylene blue can inhibit the growth and acid production metabolism of Streptococcus matans and acid production metabolism of i-PGM.
Wang
Cheng-long
CL
Dept. of Stomatology, General Hospital of PLA , Beijing 100853, China.
Liu
Hong-chen
HC
Li
Zhen-gang
ZG
Shen
Shi-jie
SJ
Chu
Bing-feng
BF
Zhao
Min
M
Huang
Li-zi
LZ
D003731:Dental Caries; D003773:Dental Plaque; D006019:Glycolysis; D008751:Methylene Blue; D013295:Streptococcus mutans
D008751:Methylene Blue