OBJECTIVETo compare the antibacterial effect between sodium fluoride and Galla Chinesis in bioflim model. To evaluate the feasibility of application of Gala Chinesis in the clinical practice of caries prevention.

METHODSStreptococcus mutans, Streptococcus sanguis, Streptococcus salivarius and Actinomyces naeslundii had been chosen as the experimental bacteria. In the experiment, biofilmn model was constructed, and two agents were added in the media. After a period of continuous culture, the number of bacteria adhering on the HA disc was examed, the planktonic pH in the flow cell was recorded continuously, and the morphology of the biofilmn formed on the HA disc was observed by SEM.

RESULTS(1) Galla Chinesis could inhibit the growth of the four oral bacteria in the biofilm just as sodium fluoride. (2) Galla Chinesis and sodium fluoride could prevent the descent of the planktonic pH in the flow cell, but Galla Chinesis was less efficient than sodium fluoride. (3) The biofilms formed after application of Galla Chinesis and fluoride, but the bacterial cells had less matrix than those applicated with sucrose.

CONCLUSIONGalla Chinesis is one kind of effective cariostatic natural agents.