The effect of parabens in a mouthwash and incorporated into a sustained release varnish on salivary bacteria

Objectives: The purpose of this study was to evaluate the antimicrobial eff icacy of parabens, in a mouthwash and in a slow release device, against car iogenic bacteria in the oral cavity. Methods: Parabens were formulated in a mouthwash or in a topical slow release varnish preparation. In two separat e studies, volunteers were asked to use the mouthwash or the slow release v arnish applied in a personal night guard device. The levels of mutans strep tococci (MS), Lactobacilli (LB) and total cultivated bacteria were measured before and after using the mouthwash or the slow release varnish. Results: The mouthwash containing parabens had a minor and a short-term eff ect on MS and LB counts in human saliva. The use of slow release varnish co ntaining parabens, applied in a night guard, had a prolonged antibacterial effect on both MS and LB counts. Conclusions: Parabens in a mouthwash had little effect on oral bacteria cou nts; however, paraben in the slow release device had a significant and an e xtended effect in reducing oral bacteria. Although substantial reductions i n oral bacterial counts were recorded after the use of parabens in a slow r elease device, this effect could probably be enhanced by an improved pharma ceutical formulation. (C) 1999 Elsevier Science Ltd. All rights reserved.