Method: S. mutans (UA159) biofilms were formed on blocks of bovine enamel of predetermined surface hardness (SH) and were incubated at 37oC in 5% CO2 for 5 days. The biofilms were grown in ultrafiltered tryptone-yeast extract broth containing 0.10 mM glucose and they were exposed 8x/day to 10% sucrose solution for 3 min. From the 3rd day of growth, the biofilms were subjected 2x/day for 1 min to the treatments: G1) 0.9% NaCL (Negative control); G2) 0.12% Chlorhexidine digluconate (Standard Sigma - positive control); G3) Periogard (Colgate) G4) Noplak (Daught) G5) Noplak Max (Daught) and G6) Perio Therapy (Bitufo). After 5 days of growth the biofilms were collected and dry weight and viable bacteria were determined. Enamel SH was again determined and the percentage of loss (%SHL) was calculated. The experiment was conducted in triplicates and repeated three times (n=9). Biofilm and enamel were also analyzed after 2 days of growth, before starting the treatments (baseline).
Result: All mouthrinses reduced significantly the biofilms biomass compared with NaCl (p<0.05), except the Perio Therapy that did not differ from NaCl (p>0.05). All mouthrinses reduced significantly enamel demineralization compared with the NaCl (p<0.05) but the mouthwash Perio Therapy was less effective. Statistically significant increase of %SHL was observed for the treatment with Perio Therapy, the other mouthwashes did not differ from the baseline group.
Conclusion: Mouthwash Perio Therapy does not have antimicrobial activity against S. mutans biofilm and did not avoid enamel demineralization, suggesting that the detergent sodium laurylsarcosinate may be inhibitor of CHX effect. (Supported by CAPES, PROCAD 251/2007;304/2009)