Ação do fluoreto de sódio sobre a formação de depósitos, “in vitro”, por bactérias placogênicas [Title in english no available]

Abstract

The author investigated the action of sodium fluoride at the concentration of 9,2% and 1 ppm of flúor (respectively used as mouthrinses and added to water consumed by population, in dental caries prevention) "in vitro", on dental plaque forming bacteria (Streptococcus mutans, samples AHT and IB). These concentrations were selected for the present study because its application does not require previous dental prophylaxis. Thus, any possible change in the deposit formation would be the result of the action caused by the chemical agent and not by any other external factor. The developed technique was based on the determination, by dry weight of the material placed over "STICKS" of stainless steel kept inside the culture medium, where the bacteria grew. The results did not show any statistically significant changes (at the Ievel of l%) when 1 ppm of fluor was added to the cultures. On the other hand, it was noticed a reduction statistically significant (at the level of 1%), in the deposit accumulated when it was added sodium fluoride at 0.2%.