Atividade antimicrobiana de produtos fluoretados sobre bacterias formadoras do biofilme dentario: estudo in vitro / Antimicrobial activity of fluoridated products on biofi lm-forming bacteria: an in vitro study

RESUMO

Objetivo: Avaliar a atividade antimicrobiana de produtos fluoretados sobre cepas de referencia de Streptococcus mutans, Streptococcus oralis e Lactobacillus casei. Metodo: Comparou-se os produtos a base de diaminofluoreto de prata (Cariestop© a 12%, Cariostal© a 16% e o Cariestop© a 30%), gel acidulado (Flutop©) e espuma acidulada (Fluor Care©), sob a forma pura e em seis diluicoes (1:2 a 1:64), determinando-se a Diluicao Inibitoria Maxima (DIM) com a clorexidina (controle positivo). Para verificacao a DIM, utilizou-se o metodo da difusao em agar e a tecnica do agar recortado, posterior incubacao em microaerofilia por 48 horas, seguindo-se da mensuracao dos halos de inibicao. Os testes foram realizados em duplicata, procedendo-se a analise descritiva dos dados.Resultados: O Cariostal a 16% teve sua DIM de 25% sobre o S. mutans, evidenciando-se inibicao sobre o S. oralis na sua forma pura. Em relacao ao Cariestop a 30%, constatou-se que ele inibiu o S. mutans e o S. oralis na sua forma pura e na diluicao de ate 1:2, sendo o unico produto testado a formar halo de inibicao para o L. casei (forma pura). A espuma acida nao demonstrou atividade antimicrobiana sobre as cepas testadas enquanto o gel de fluorfosfato acidulado inibiu o crescimento de S. mutans e S. oralis apresentando a DIM de 50% sobre estas bacterias. Conclusao: A maioria dos cariostaticos apresentou atividade antimicrobiana sobre S. mutans e S. oralis. O gel demonstrou acao antimicrobiana sobre S. mutans e S. oralis, nao sendo evidenciado efeito sobre o L. casei enquanto tal atividade nao foi verificada para a espuma sobre as cepas testadas.

ABSTRACT

Objective: To evaluate the antimicrobial activity of fluoridated products on reference strains of Streptococcus mutans, Streptococcus oralis and Lactobacillus casei. Method: The antibacterial activity of products based on silver diamine fluoride at 12% (Cariestop©), 16% (Cariostal©) and30% (Cariestop©), acidulated phosphate fluoride gel (Flutop©) and acidulated phosphate fluoride foam (Fluor Care©) in their pure form and in 6 dilutions (1:2 to 1:64) was evaluated bydetermination of the maximum inhibitory dilution (MID), having chlorhexidine as the positive control. For determination of the MID, the agar difuusion method and the agar well techniquewere performed, followed by incubation in microaerophilia for 48 hours. The analysis of MID data was based on the measurement of the zones of bacterial growth inhibition (inmm) formed around the wells. All tests were performed in duplicate and the data were analyzed descriptively. Results: Cariostal© presented 25% MID against S. mutans, inhibited of S.oralis in its pure form. Cariestop© inhibited S. mutans and S. oralis in its a form and in dilutions up to 1:2,being the only product that formed an inhibition zone against L. casei (pure form). The acidulated phosphate fluoride foam did not show antimicrobial activity against the tested strains, thewhile acidulated phosphate fluoride gel inhibited the growth of S. mutans and S. oralis, presenting 50% MID against the bacteria Conclusion: Most cariostatic agents presented antimicrobial activity against S. mutans and S. oralis. The acidulated phosphate fluoride gel showed antimicrobial action against S. mutans and S. oralis, but had not effect against L. casei. The acidulated phosphate fluoride foam showed no antimicrobial activity against the tested strains.