Avaliou-se a acao antibacteriana do Diamino Fluoreto de Prata (CariestopR) nas concentracoes comerciais de 12% e 30% frente as linhagens clinicas de Estreptococos do Grupo Mutans (EGM) e padrao (ATCC 25175) de S. mutans. Os isolados clinicos foram obtidos da saliva de seis criancas atendidas na Clinica de Odontopediatria da UFPB, sendo agrupados em: GI-baixo risco/atividade de carie; GII-alto risco/atividade de carie. Apos semeadura, as cepas foram isoladas em Agar Mitis-Salivarius e divididas em sete grupos - M1 (linhagem padrao) a M7. Determinou-se a acao antibacteriana por meio da Diluicao Inibitoria Maxima (DIM) pelo metodo da difusao em agar, utilizando-se diluicoes seriadas (1:1 a 1:32) das formulacoes puras dos cariostaticos e da clorexidina a 0,12% (controle positivo). Apos incubacao, mensurou-se os halos de inibicao. A acao bactericida e bacteriostatica, das substancias puras e nas suas respectivas DIMs, foi avaliada pela prova do poder germicida, utilizando-se corpos de provas de vidro, inoculados pelas cepas e incubados por 24h em meio BHI. Cada corpo de prova foi exposto aos cariostaticos e a clorexidina por 30s, 3min, 30min e 1h entao inseridos em caldo BHI e incubados por 24h. As amostras foram repicadas em Agar Mitis-Salivarius para avaliacao da acao bactericida ou bacteriostatica das substancias. A analise dos dados foi comparativo-descritiva. O CariestopR a 30% foi eficaz ate a ultima diluicao (1:32), frente todas as cepas. Para o CariestopR a 12%, as DIMs corresponderam a ultima diluicao (1:32) em todas as amostras, exceto para M3 (1:8). A clorexidina apresentou DIM na ultima concentracao (1:32) em cinco amostras, sendo 1:8 para M3 e M7. A prova do poder germicida identificou acao bactericida das substancias nos tempos analisados, para todas as amostras. Concluiu-se que os cariostaticos apresentaram acao antibacteriana quando comparados a clorexidina e estas duas substancias exerceram acao bactericida frente as cepas, em todos os tempos de contato.
The antibacterial activity of Silver Diamine Fluoride - SDF - (CariestopR), at commercial concentrations of 12% and 30%, was evaluated against clinical and pattern strains (ATCC 25175) of S. mutans. Clinical isolates were obtained from the saliva of six children attending the Pediatric Dentistry Clinic UFPB, being grouped as follows: GI- low risk and caries activity, GII- high risk and caries activity. Once sown, the strains were isolated from Mitis-Salivarius Agar and divided into seven groups - M1 (pattern strain) to M7. The antibacterial activity was determined by maximum inhibitory dilution (MID) by the agar diffusion method, using serial dilutions (1:1 to 1:32) and the pure formulations of SDF and chlorhexidine 0.12% (positive control). After incubation, the inhibition zones were measured. The bactericidal and bacteriostatic actions of pure substances and in their respective MIDs were evaluated by test of germicidal power, using glass specimens, after inoculation by the strains and incubation for 24 hours in BHI broth. Each specimen was exposed to chlorhexidine and to SDF for 30s, 3min, 30min and 1h, then incubated for 24 h in BHI broth. The samples were subcultured in Mitis-Salivarius Agar to evaluate the bactericidal or bacteriostatic activity of the substances. The data were analyzed in a comparative-descriptive method. The CariestopR 30% was effective until the last dilution (1:32) on all strains. For CariestopR 12%, the MIDs corresponded to last dilution (1:32) in almost all samples, except for M3 (1:8). Chlorhexidine showed DIM in the last concentrations (1:32) on five samples, and in the concentration 1:8 for M3 and M7. As evidence of the germicidal power, the substances had bactericidal activity at all times analyzed. It was concluded that the cariostatic showed antibacterial activity when compared to chlorhexidine and these two substances presented bactericidal action against the strains at all contact times.
