Influência da contaminação cavitária na adaptação marginal das restaurações de resina composta / Influence of cavity contamination on marginal adaptation of composite resin restorations

Objetivo: avaliar a influencia da contaminação cavitária na adaptação marginal das restauraçõesde resina composta e a associação da lisozima ao sistema adesivo. Materiais e Métodos:Foram selecionados 40 terceiros molares permanentes e confeccionados preparos cavitários classeV com pontas diamantadas cilíndricas 1090 (4 mm de largura, 6 mm de comprimento e 1,5 mmde profundidade). Todos os dentes foram esterilizados e divididos aleatoriamente em 4 grupos(n=10): G1: sistema adesivo (SA) e restauração com resina composta (RC); G2: cavidadescontaminadas com 10 μl de Streptococcus mutans (0,5 de Mc Farland), SA e RC; G3:sistema adesivo associado com lisozima (ADL) e RC e G4: cavidades contaminadas com 10 μlde Streptococcus Mutans (0,5 de Mc Farland), ADL e RC. A lisozima foi adicionada ao SA com ummicrobrush embebido no SA e na lisozima em pó. Os dentes foram impermeabilizados e imersosem azul de metileno por 4 horas a 37ºC. Os dentes foram seccionados e fotografados. Resultados:A avaliação da microinfiltração foi feita por dois avaliadores utilizando o Programa Tpsdig. Paraavaliar a calibração entre os examinadores, foi utilizado o teste de Correlação de Pearson. As médiasdas porcentagens de fendas e bolhas foram submetidas ao teste de Kruskal Wallis com 5% designificância. Conclusão: a contaminação cavitária com Streptococcus mutans acarretou na formaçãode fendas entre a resina composta e as margens cavitárias. A lisozima associada ao sistemaadesivo não influenciou na formação de fendas e bolhas nas restaurações de resina composta.

Objective: evaluate the influence of cavity contamination on marginal adaptation of compositerestorations and the association of lysozyme to the adhesive system. Materials and Methods:Were selected 40 permanent third molars and made cavity preparations class V with cylindricaldiamond burs 1090 (4 mm wide, 6 mm long and 2 mm deep). All teeth were sterilized and randomlydivided into 4 groups (n = 10): G1: adhesive system (SA) and restoration with compositeresin (CR); G2: cavity contaminated with 10 μl of Streptococcus mutans (0.5 McFarland), SA andRC; G3: adhesive system associated with lysozyme (ADL) and RC and G4: cavity contaminated with10 μl of Streptococcus mutans (0.5 Mc Farland), ADL and RC. Lysozyme was added to the SA witha microbrush embedded in the SA and powdered lysozyme. The teeth were sealed and immersedin a methylene blue for 4 hours at 37 ° C. The teeth were sectioned and photographed. Results:The evaluation of microleakage was made by two reviewers using the Tpsdig Program. To assessthe calibration of examiners, we used the Pearson correlation test. The mean percentages of cracksand bubbles were submitted to Kruskal Wallis test at 5% significance level. Conclusion: the cavityStreptococcus mutans contamination resulted in the formation of cracks between the compositeresin and the cavity margins. Lysozyme associated with the adhesive system did not influence theformation of cracks and bubbles in the composite restorations.

Avaliação dos métodos de higienização sobre S. mutans dos protetores bucais / Evaluation of cleaning methods on custom-made mouthguards of S. mutans

Objetivo: avaliar a eficácia de três diferentes métodos de higienização sobre cepas de S.mutans dos protetores bucais feitos sob medida: dentifrício fluoretado, detergente neutro eclorexidina. Materiais e Métodos: foram confeccionados 30 protetores bucais feitos sob medida com placas de silicone de 3 mm que foram contaminados em meio de sobrevivência BHI (BrainHeart Infusion) suplementado com 1% de glicose e sacarose e 0,5% de extrato de levedura e incubados em jarra de anaerobiose a 37°C em estufa bacteriológica por 15 dias. O meio foi renovado a cada 24 horas. Após a contaminação, foi feita a coleta dos protetores bucais, esfregaço e plaqueamento na superfície do meio de cultura mitis salivarius com bacitracina. Os protetores foram higienizados com escova dental, com três diferentes meios de higienização:dentifrício fluoretado, detergente neutro e clorexidina e, após a higienização foram submetidos a uma nova coleta, esfregaço e plaqueamento. Após incubação, foi feita a contagem do total de bactérias viáveis. Os resultados obtidos foram submetidos à análise estatística e ao teste não paramétrico de Wilcoxon. Resultados: houve redução microbiana significativa da contagem deS. mutans utilizando clorexidina e detergente (p<0.05). Não houve diferença significante na contagem antes e depois utilizando o dentifrício (p>0.05). Conclusão: a clorexidina e o detergente podem ser utilizados para desinfecção dos protetores bucais.

Objective: The effect of three different cleaning methods on custom-made mouth guards’strains of S. mutans: fluoridated tooth paste, neutral detergent and chlorhexidine. Materials and Methods: it were made 30 mouthguards custom-made with 3mm silicone slabs that have been subjected to a microbiological processing in supplemented BHI (Brain Heart Infusion). They were in cubated in anaerobic jar at 37 ° bacteriological green house for 15 days, changing the medium every 24 hours. After the contamination, samples were drawn and it was made the collection, smear and plating on surface of the culture medium mitis salivarius with bacitracin and then they were cleaned with tooth brush with three different modes of cleaning: chlorhexidine, neutral detergent and fluoridated tooth paste. After incubation, the count was made of total viable bacteria. The results were statistically analyzed by the Wilcoxon non-parametric test. Results: there wasa significant reduction in microbial counts before and after using chlorhexidine and detergent (p<0.05). There wasn’t significant difference in the count before and after using the tooth paste(p>0.05). Conclusion: chlorhexidine and detergent can be used for disinfection of mouth guards

Typing of Streptococcus mutans strains isolated from caries free and susceptible subjects by multilocus enzyme electrophoresis

This study was evaluated the clonal diversity of Streptococcus mutans in caries-free and caries-active subjects using MLEE. Strains from caries-free subjects were grouped in a single taxon. Unrooted dendrogram showed that different strains clustered in four different clades, also showed that more than one clonal type can be found in a same individual.

Genotypic and phenotypic analysis of S. mutans isolated from dental biofilms formed in vivo under high cariogenic conditions

The oral cavity harbors several Streptococcus mutans genotypes, which could present distinct virulence properties. However, little is known about the diversity and virulence traits of S. mutans genotypes isolated in vivo under controlled conditions of high cariogenic challenge. This study evaluated the genotypic diversity of S. mutans isolated from dental biofilms formed in vivo under sucrose exposure, as well as their acidogenicity and aciduricity. To form biofilms, subjects rinsed their mouths with distilled water or sucrose solution 8 times/day for 3 days. S. mutans collected from saliva and biofilms were genotyped by arbitrarily-primed PCR. Genotypes identified in the biofilms were evaluated regarding their ability to lower the suspension pH through glycolysis and their acid susceptibility and F-ATPase activity. Most subjects harbored only one genotype in saliva, which was detected in almost all biofilm samples at high proportions. Genotypes isolated only in the presence of sucrose had higher acidogenicity than those isolated only in the presence of water. Genotypes from biofilms formed with sucrose were more aciduric after 30 and 60 min of incubation at pH 2.8 and 5.0, respectively. The present results suggest that biofilms formed under high cariogenic conditions may harbor more aciduric and acidogenic S. mutans genotypes.

A cavidade oral apresenta vários genótipos de Streptococcus mutans, que podem possuir diferentes capacidades de virulência. Entretanto, pouco se sabe sobre a diversidade e virulência de genótipos de S. mutans isolados in vivo sob uma condição controlada de alto desafio cariogênico. Este estudo avaliou a diversidade genotípica de S. mutans identificados no biofilme dental formado in vivo na presença de sacarose, assim como a acidogenicidade e aciduricidade desses genótipos. Para possibilitar formação de biofilme, voluntários bochecharam com água destilada ou solução de sacarose 8x/dia durante 3 dias. S. mutans isolados da saliva e do biofilme dental foram genotipados por PCR com primers-arbitrários. Genótipos isolados do biofilme foram avaliados em relação à habilidade de reduzir o pH da suspensão devido à glicólise, em relação à susceptibilidade a ácidos e também atividade F-ATPase. A maioria dos voluntários apresentou apenas 1 genótipo na saliva, que foram detectados em quase todas as amostras de biofilme em altas proporções. Genótipos isolados somente na presença de sacarose apresentaram maior acidogenicidade do que aqueles genótipos isolados apenas na presença de água. Genótipos de biofilmes formados na presença de sacarose foram mais acidúricos após 30 e 60 min de incubação em pH 2,8 e 5,0, respectivamente. Os resultados do presente estudo sugerem que biofilmes formados sob condição de alto desafio cariogênico podem apresentar genótipos de S. mutans mais acidúricos e mais acidogênicos.

Evaluation of genotypic diversity of Streptococcus mutans using distinct arbitrary primers

Streptococcus mutans has been considered one of the main etiological agents of dental caries and the genotypic diversity rather than its salivary counts may be considered as a virulence factor of this bacterium. For genotyping with polymerase chain reaction (PCR) with arbitrary primers, several primers have been used in order to improve complexity and specificity of amplicon patterns. Thus, the aim of this study was to evaluate the degree of agreement of genotypic identification among AP-PCR reactions performed with 5 distinct arbitrary primers of S. mutans isolated from saliva. Stimulated saliva was collected from 11 adult volunteers for isolation of S. mutans, and a total of 88 isolates were genotyped with arbitrary primers OPA 02, 03, 05, 13 and 18. Fourteen distinct genotypes were identified in the saliva samples. Most volunteers (9 out of 11) presented only one genotype. The results of the present study suggest that primers OPA 02, 03, 05 and 13 were suitable for genotypic identification of S. mutans isolates of saliva from adult volunteers.

Bacteriocins in S. mutans strains isolated from children with and without dental caries: biotypes and sensitivity to antibiotics

El objetivo de este estudio fue determinar la producción debacteriocinas en cepas de Streptococcus mutans aisladas de niños preescolares con y sin caries dental. Con este fin en sedeterminó el índice ceod y se tomó saliva no estimulada en 53 niños con edades entre 3 y 5 años. Las muestras de saliva se cultivaron en Agar Mitis Salivarius Bacitracina para el aislamiento selectivo y recuento de S. mutans, y se incubaron en anaerobiosis durante 2 días a 37°C. Las cepas de S. mutans aisladas se biotipificaron con el sistema enzimático Api-ZYM (bioMérieux; Marcy-lE´toile, Francia). La detección de bacteriocinas se realizó de acuerdo a la técnica de doble capa enagar infusión cerebro corazón y las concentraciones mínimas inhibitorias de los aislamientos fueron evaluados contra la penicilina, amoxicilina, cefazolina, eritromicina, clindamicina,imipenem y vancomicina, por el método de dilución en agar. La experiencia de caries dental en esta población fue de 66 por ciento (35/53) y el índice ceod promedio fue de 3.2 (rango 2-6).S. mutans fue aislado en 33 de los 53 niños incluidos en el estudio (62 por ciento). Las 33 cepas de S. mutans aisladas se agruparon en 10 biotipos. Ocho (24 por ciento) de las 33 cepas evaluadas produjeron bacteriocinas, 6 de estas cepas provinieron de pacientescon caries y las otras dos de pacientes sin caries. Todos los 33 aislamientos de S. mutans fueron altamente sensibles a los antibacterianos evaluados.

Estudio comparativo de medios de cultivo para crecimiento y recuperación del Streptococcus mutans ATCC 25175 in vitro / Comparative study of cultivation means for growth and recovery of the streptococcus mutans ATCC 25175

El presente estudio evaluó la recuperación in vitro de S. mutans ATCC 25175 en siete medios de cultivo:Mitis Salivarius Agar (MSA), Mitis Salivarius Agar-Bacitracina (MSB), Mitis Salivarius AgarKanamicina Bacitracina (MSKB), Mitis Salivarius Agar-Bacitracina Sulfisoxazol (MS-MUT), Tripticasa soya-Extracto de levadura-Sucrosa-Bacitracina Agar (TYS20B) (medios referenciados como selectivos), Agar Infusión Cerebro Corazón (BHI) (medio de enriquecido) y Agar Todd Hewitt (TH) (medio selectivo para Streptococcus). Se demostró una mayor recuperación del microorganismo en el medio TYS20B,seguido en orden decreciente de los medios: BHI, MSA, TH, MS-MUT, MSB y MSKB. El medio TYS20B, fue el más adecuado para el microorganismo; presentando un porcentaje de recuperación significativamente mayor a los demás medios selectivos evaluados, coincidiendo con el éxito obtenido en otros estudios para recuperación de S.mutans

Relationship between caries status, colony forming units (cfu) of Streptococcus mutans and Snyder caries activity test.

It is a well established fact that dental caries is caused by streptococcus mutans. For qualitative and quantitative analysis of streptococcus mutans, saliva samples are often preferred and are processed according to Kohler and Brathall method. In the present study an attempt is made to relate caries status (caries free, average caries, and rampant caries group) with cfu counts of streptococcus mutans and Snyder test. The streptococcus mutans were isolated using MSB agar and cfu were determined of each individual from different caries groups. The saliva of the same individual was drooled into a culture bottle containing Snyder test agar and extent of colour change was observed after 24, 48, and 72 hours incubated at 37 degrees C. The time and extent of colour change determined the conduciveness of diet. It has been observed that caries free individuals have low cfu count and their diet was mild or moderately conducive, while the individuals having average caries had medium cfu count and their diet was moderately-high conducive. In rampant caries, individuals however the cfu count were high and the diet was highly conducive. In caries free, average caries and rampant caries group 40, 60, and 80 per cent samples showed colour change, in Snyder test up to full length in 72 hours respectively. Thus a definite correlation exists between caries status, cfu count of streptococcus mutans and Snyder caries activity test.