Efeito antibacteriano de antissépticos bucais frente ao S. mutans, E. faecalis e P. aeruginosa

Abstract

Purpose:to evaluate the antibacterial effect of oral antiseptics (cetylpyridinium chloride, chlorhexidine gluconate and benzalkonium chloride) on S. mutans, E. faecalis andP. aeruginosa, determined by agar diffusion test and direct exposition test. Methods:The strains were inoculated in 7 mL BHI and incubated at 37°C for 24 hours. For agar diffusion test, 13 Petri plates with 20 mL BHIA were inoculated with 0.1 mL of microbial suspensions, aided by sterilized swabs, obtaining a confluent growth. Thirty six paper discs with 9 mm diameter were immersed in experimental solutions (cetylpyridinium chloride 0.07%, cetylpyridinium chloride 0.075%, chlorhexidine gluconate 0.12% and benzalkonium chloride 1.30 mg)for 1 minute. Following, at each plate, 3 paper discs containing irrigant solutions were put on BHIA surface. The plates were kept for 1 hour at environmental temperature and incubated at 37°C for 48 hours. Inhibition zones were measured over the paper discs containing the solutions, using two perpendicular measurements and obtaining the mean value. For direct exposition test, 516 sterilized paper points #50 were immersed on microorganisms suspension for 5 minutes, put in Petri plates and covered with 10 mL of irrigant solution. At 1, 5, 10 and 30 minutes intervals, 3 paper points were removed from substances contact, transported individually and immersed in 7 mL Letheen Broth, and incubated at 37°C for 48 hours. Bacterial growth was evaluated by medium turbidity. An inoculum of 0.1 mL Letheen Broth was transferred to 7 mL BHI, and incubated at the same conditions previously described. Bacterial growth was again evaluated by medium turbidity. Results: Inhibition zones were greater than 10 mm for all substances and in microorganisms tested. Benzalkonium chloride presented antibacterial effect against the biological markers after 12 5 minutes in direct exposition, while cetylpyridinium chloride and chlorhexidine gluconate presented antibacterial effect against all the microorganisms after 10 minutes. Conclusion:Theantiseptic solutions presented antibacterial effect against S. mutans, E. faecalis e P. aeruginosa.