ABSTRACT
Abstract: The purpose of this study was to evaluate the antimicrobial properties of a new formulation containing silver nanoparticles, named Nano Silver Fluoride (NSF), to inhibit Streptococcus mutans biofilm formation on children's dental enamel. The variations in dental biofilm pH and in the Simplified-Oral-Hygiene-Index (OHI-S) also were evaluated after the treatment with NSF. This was a randomized, double-blind, crossover and prospective pilot clinical trial study in which 12 schoolchildren, aged between 7-8 years, had their dental enamel treated with two solutions: S1 - Nano Silver Fluoride and S2 - negative control (saline solution), in different experimental moments. The dental biofilm adhered to enamel treated with NSF had lower values of S. mutans viability (absorbance) and colony forming units (CFU) than the S0 (baseline) and S2. There was a statistically significant difference between the OHI-S mean values of S0 and S1. There were no differences between the biofilm pH (both before and after the use of the test substances) and among the different groups. These properties suggest that NSF has bactericidal effect against S. mutans biofilm and it may be used for clinical control and prevention of dental biofilm formation.
Resumo O objetivo do presente estudo foi avaliar as propriedades antimicrobianas de uma nova formulação composta por nanopartículas de prata, denominada nano silver fluoride (NSF), na inibição de biofilme de Streptococcus mutans sobre a superfície do esmalte dentário de crianças. Variações no pH do biofilme dental e nos valores do índice de Higiene Oral Simplificada (IHO-S) também foram avaliadas após o tratamento com NSF. Trata-se de um estudo piloto, randomizado, duplo cego, cruzado e prospectivo. A amostra foi composta por 12 crianças, de ambos os gêneros, com idades entre 7 e 8 anos, as quais utilizaram as duas soluções testes, S1- NSF e S2- controle negativo (solução salina). O biofilme dental tratado com NSF apresentou menores valores de viabilidade de S. mutans (absorbância) e de unidades formadoras de colônias (UFC) do que o biofilme baseline e o biofilme tratado com S2. Houve diferença estatisticamente significativa entre os valores médios de IHO-S dos grupos baseline e S1, com uma redução dos valores. Não houve qualquer variação nos valores de pH do biofilme dental, antes e depois do tratamento com S1 e S2 e entre os diferentes grupos. Estas propriedades sugerem que NSF possui efeito bactericida sobre o biofilme de S. mutans, podendo ser utilizado clinicamente para o controle e prevenção da formação do biofilme dentário.
Subject(s)
Humans , Male , Female , Child , Biofilms , Metal Nanoparticles/chemistry , Silver/chemistry , Streptococcus mutans/drug effects , Colony Count, Microbial , Cross-Over Studies , Double-Blind Method , Hydrogen-Ion Concentration , Oral Hygiene Index , Pilot Projects , Prospective Studies , Streptococcus mutans/physiologyABSTRACT
Objective: to clarify the benefits related to the use of silver nanoparticles (AgNPs) in the prevention of dental caries in children, we compared the antibacterial pro-perties of silver nanoparticles, chlorhexidine, and silver diamine fluoride (SDF) to Streptococcus mutans. Mate-rials and method: to analyze the minimum inhibitory concentration (MIC) we used the spectrophotometric microdilution method (SMM), and turbidity. We also verified the minimum bactericidal concentration (MBC) of the target products. Analysis of variance (ANOVA) was used to compare MIC and MBC among the groups studied. Results: regarding antimicrobial proprieties, the tested substances showed effective bacteriostatic and bactericide activity. The silver nanoparticles had the lowest value of MIC against reference strains (ATCC 25175) (p < 0.05). In clinical strains, the MIC value of silver nanoparticles was comparable to that of chlorhe-xidine (p > 0.05), and lower than SDF (p < 0.05). Con-clusion: silver nanoparticles proved to have antimicro-bial activity against S. mutans, therefore, they may be an effective agent in the prevention of dental caries