Estudio in vitro del Efecto Antibacteriano de la Oleorresina de Copaifera reticulata y el Aceite Esencial de Origanum majoricum Frente a Streptococcus mutans y Enterococcus Faecalis Bacterias de Importancia en Patologías Orales / In vitro Study of the Antibacterial Effect of Oleoresin of Copaifera reticulata and the Essential Oil of Origanum majoricum against Streptococcus mutans and Enterococcus faecalis Bacteria of Importance in Oral Pathologies

RESUMEN: El objetivo del estudio fue determinar el efecto antibacteriano in vitro de la oleorresina de Copaifera reticulata (C. reticulata) "copaiba" y del aceite esencial de Oreganum majoricum (O. majoricum) "orégano" frente a Streptococcus mutans (S. mutans) y Enterococcus faecalis (E. faecalis). Se desarrollaron pruebas de sensibilidad activando primero las cepas bacterias a enfrentar. La oleorresina de copaiba fue diluida con dimetilsulfósido (DMSO), obteniéndose al final concentraciones a probar de 100 %, 50 %, 25 %, y 12,5 %. En relación al aceite esencial de orégano este se probó solamente al 100 %. Para la prueba de difusión en agar con discos, se tomaron inóculos 100 µL de cada cepa bacteriana a una turbidez de 0,5 de Mc Farlam, para ser sembrados por diseminación en placas de tripticasa soya agar, para luego colocar los discos de forma equidistante cargados con las diferentes concentraciones de los productos naturales, se utilizaron como control positivo a la clorhexidina al 0,12 % y al DMSO como control negativo. Se incubaron las placas por el método de la vela en extinción a 37 °C, por un periodo de 24 horas, pasado el tiempo se realizó la lectura de los halos de inhibición. Los resultados obtenidos por la copaiba, determinaron un efecto antibacteriano en sus cuatro concentraciones, siendo los mayores halos de inhibición a la concentración del 100 %, copaiba genero mayores halos promedios para S, mutans de 30,00 ± 0,00 mm y para E. faecalis de 8,3 ± 0,50 mm. Para el caso del orégano se producen halos a la concentración del 100 % con un promedio de 25,3 ± 0,96 mm para S. mutans y para E. faecalis de 9,5 ± 1,29 mm. Se concluye del estudio que tanto copaiba como el orégano presentan un efecto antibacteriano para ambas bacterias, siendo su mayor efecto antibacteriano para ambos productos naturales sobre S. mutans.

ABSTRACT: The objective of the study was to determine the in vitro antibacterial effect of the oleoresin of Copaifera reticulata (C. reticulata) "copaiba" and of the essential oil of Oreganum majoricum (O. majoricum) "oregano" against Streptococcus mutans (S. mutans) and Enterococcus faecalis (E. faecalis). Sensitivity tests were developed by first activating the bacteria strains to be confronted. The oleoresin of copaiba was diluted with dimethylsulphoside (DMSO), obtaining final concentrations to be tested of 100 %, 50 %, 25 %, and 12.5 %. In relation to the essential oil of oregano, it was only 100 % tested. For the disk agar diffusion test, 100 mL of each bacterial strain was taken at a turbidity of 0.5 of Mc Farlam, to be planted by dissecting trypticase soy agar plates, and then placing the disks equidistantly loaded with the different concentrations of natural products; 0.12 % chlorhexidine was used as a positive control and DMSO as negative control. The plates were incubated by the candle method in extinction at 37 °C, for a period of 24 hours, after which time the inhibition halos were read. The results obtained by the copaiba, determined an antibacterial effect in its four concentrations, being the biggest halos of inhibition at the concentration of 100 %, copaiba genus higher average halos for S. mutans of 30.00 ± 0.00 mm and for E. faecalis of 8.3 ± 0.50 mm. In the case of oregano, haloes are produced at a concentration of 100 % with an average of 25.3 ± 0.96 mm for S. mutans and for E. faecalis 9.5 ± 1.29 mm. It is concluded from the study that both copaiba and oregano present an antibacterial effect for both bacteria, being its greater antibacterial effect for both natural products on S. mutans.

Removal and killing of multispecies endodontic biofilms by N-acetylcysteine

ABSTRACT Removal of bacterial biofilm from the root canal system is essential for the management of endodontic disease. Here we evaluated the antibacterial effect of N-acetylcysteine (NAC), a potent antioxidant and mucolytic agent, against mature multispecies endodontic biofilms consisting of Actinomyces naeslundii, Lactobacillus salivarius, Streptococcus mutans and Enterococcus faecalis on sterile human dentin blocks. The biofilms were exposed to NAC (25, 50 and 100 mg/mL), saturated calcium hydroxide or 2% chlorhexidine solution for 7 days, then examined by scanning electron microscopy. The biofilm viability was measured by viable cell counts and ATP-bioluminescence assay. NAC showed greater efficacy in biofilm cell removal and killing than the other root canal medicaments. Furthermore, 100 mg/mL NAC disrupted the mature multispecies endodontic biofilms completely. These results demonstrate the potential use of NAC in root canal treatment.

Influence of Helicobacter pylori culture supernatant on the ecological balance of a dual-species oral biofilm

Abstract Dental caries is a chronic progressive disease occurring in the tooth hard tissue due to multiple factors, in which bacteria are the initial cause. Both Streptococcus mutans and Streptococcus sanguinis are main members of oral biofilm. Helicobacter pylori may also be detected in dental plaque, playing an important role in the development of dental caries. Objective The aim of this study was to investigate the effect of H. pylori culture supernatant on S. mutans and S. sanguinis dual-species biofilm and to evaluate its potential ability on affecting dental health. Material and methods The effect of H. pylori supernatant on single-species and dual-species biofilm was measured by colony forming units counting and fluorescence in situ hybridization (FISH) assay, respectively. The effect of H. pylori supernatant on S. mutans and S. sanguinis extracellular polysaccharides (EPS) production was measured by both confocal laser scanning microscopy observation and anthrone-sulfuric acid method. The effect of H. pylori supernatant on S. mutans gene expression was measured by quantitative real-time PCR (qRT-PCR) assays. Results H. pylori supernatant could inhibit both S. mutans and S. sanguinis biofilm formation and EPS production. S. sanguinis inhibition rate was significantly higher than that of S. mutans. Finally, S. mutans bacteriocin and acidogenicity related genes expression were affected by H. pylori culture supernatant. Conclusion Our results showed that H. pylori could destroy the balance between S. mutans and S. sanguinis in oral biofilm, creating an advantageous environment for S. mutans, which became the dominant bacteria, promoting the formation and development of dental caries.

AgNPs: The New Allies Against S. Mutans Biofilm - A Pilot Clinical Trial and Microbiological Assay

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.

Bacterial adhesion on conventional and self-ligating metallic brackets after surface treatment with plasma-polymerized hexamethyldisiloxane

ABSTRACT Introduction: Plasma-polymerized film deposition was created to modify metallic orthodontic brackets surface properties in order to inhibit bacterial adhesion. Methods: Hexamethyldisiloxane (HMDSO) polymer films were deposited on conventional (n = 10) and self-ligating (n = 10) stainless steel orthodontic brackets using the Plasma-Enhanced Chemical Vapor Deposition (PECVD) radio frequency technique. The samples were divided into two groups according to the kind of bracket and two subgroups after surface treatment. Scanning Electron Microscopy (SEM) analysis was performed to assess the presence of bacterial adhesion over samples surfaces (slot and wings region) and film layer integrity. Surface roughness was assessed by Confocal Interferometry (CI) and surface wettability, by goniometry. For bacterial adhesion analysis, samples were exposed for 72 hours to a Streptococcus mutans solution for biofilm formation. The values obtained for surface roughness were analyzed using the Mann-Whitney test while biofilm adhesion were assessed by Kruskal-Wallis and SNK test. Results: Significant statistical differences (p< 0.05) for surface roughness and bacterial adhesion reduction were observed on conventional brackets after surface treatment and between conventional and self-ligating brackets; no significant statistical differences were observed between self-ligating groups (p> 0.05). Conclusion: Plasma-polymerized film deposition was only effective on reducing surface roughness and bacterial adhesion in conventional brackets. It was also noted that conventional brackets showed lower biofilm adhesion than self-ligating brackets despite the absence of film.

RESUMO Introdução: a deposição de filme de polímero a plasma foi criada para modificar as propriedades de superfície dos braquetes ortodônticos metálicos, com o intuito de inibir a adesão bacteriana. Métodos: filmes finos de polímero de hexametildisiloxano (HMDSO) foram depositados em braquetes ortodônticos de aço inoxidável convencionais (n = 10) e autoligáveis (n = 10), utilizando a técnica de radiofrequência PECVD (Plasma-Enhanced Chemical Vapor Deposition). As amostras foram divididas em dois grupos, de acordo com o tipo de braquete, e dois subgrupos após o tratamento de superfície. A microscopia eletrônica de varredura (MEV) foi realizada para avaliar a presença de adesão bacteriana sobre as superfícies das amostras (região de ranhura horizontal e aletas) e a integridade da camada de filme. A Interferometria Confocal (CI) avaliou a rugosidade, e a molhabilidade superficial foi avaliada por goniometria. Para análise de adesão bacteriana, as amostras foram expostas durante 72 horas a uma solução de Streptococcus mutans, para formação de biofilme. Os valores obtidos para a rugosidade da superfície foram analisados pelo teste de Mann-Whitney, enquanto a adesão do biofilme foi avaliada pelos testes de Kruskal-Wallis e SNK. Resultados: observaram-se diferenças estatisticamente significativas (p <0,05) para a rugosidade superficial e redução da adesão bacteriana em braquetes convencionais após o tratamento da superfície, e entre braquetes convencionais e autoligáveis. Não foram observadas diferenças estatísticas significativas entre os grupos autoligáveis (p> 0,05). Conclusão: a deposição de polímero a plasma só foi efetiva na redução da rugosidade superficial e adesão bacteriana em braquetes convencionais. Observou-se, também, que os braquetes convencionais apresentaram menor adesão ao biofilme do que os braquetes autoligáveis, apesar da ausência de filme.

Influence of resin-modified glass ionomer and topical fluoride on levels of Streptococcus mutans in saliva and biofilm adjacent to metallic brackets

Abstract Decalcification of enamel during fixed orthodontic appliance treatment remains a problem. White spot lesions are observed in nearly 50% of patients undergoing orthodontic treatment. The use of fluoride-containing orthodontic materials has shown inconclusive results on their ability to reduce decalcification. The aims of this investigation were to compare the levels of Streptococcus mutans (SM) in saliva and biofilm adjacent to orthodontic brackets retained with a resin-modified glass ionomer cement (RMGIC) (Fuji ORTHO LC) and a light cured composite resin (Transbond XT), and to analyze the influence of topical application of the 1.23% acidulated phosphate fluoride (APF) on SM counts. In a parallel study design, two groups (n=14/15) were used with random allocation and high salivary SM counts before treatment. Biofilm was collected from areas adjacent to the brackets on teeth 13, 22, 33, and 41. Both saliva and biofilm were collected on the 7th, 21st, 35th, and 49th days after appliance placement. Topical fluoride application was carried out on the 35th day. Bonding with RMGIC did not alter SM counts in saliva or biofilm adjacent to the brackets. On the other hand, the biofilm adjacent to brackets retained with composite resin showed a significant increase in SM counts along the trial period. Topical application of 1.23% APF did not reduce salivary or biofilm SM counts regardless of the bonding material. In conclusion, fluoride topical application did not show efficacy in reducing SM. The use of RMGIC as bonding materials allowed a better control of SM cfu counts in dental biofilm hindering the significant increase of these microorganisms along the trial period, which was observed in the biofilm adjacent to the composite material.

Evaluation of Surface Roughness and Bacterial Adhesion on Tooth Enamel Irradiated With High Intensity Lasers

Abstract The aim was to evaluate the surface roughness and bacterial adhesion on enamel irradiated with high intensity lasers, associated or not to a fluoride varnish. Eighty fragments of bovine enamel were equally divided in 8 groups (n=10). Group 1 was not treated and Group 2 received only a 5% fluoride varnish application. The other groups were irradiated with an Er:Cr:YSGG (8.92 J/cm2), an Nd:YAG (84.9 J/cm2) and a diode laser (199.04 J/cm2), associated or not to a 5% fluoride varnish. The surface roughness was measured before and after treatments. Afterward, all samples were incubated in a suspension of S. mutans at 37 °C for 24 h. The colony-forming units (CFU) were counted by a stereoscope and the results were expressed in CFU/mm2. One-way ANOVA and the Tukey´s test compared the roughness data and the Student´s test compared the results obtained in the bacterial adhesion test (a=5%). The results showed that the irradiated samples without varnish presented the same roughness and the same bacterial adhesion that the non-irradiated samples. However, samples irradiated in the presence of fluoride varnish showed higher surface roughness and higher bacterial adhesion than the non-irradiated samples and those irradiated without varnish. Presence of pigments in the varnish increased the lasers’ action on the enamel surface, which produced ablation in this hard tissue and significantly increased its surface roughness. For this reason, the enamel’s susceptibility to bacterial adhesion was higher when the irradiation of the samples was made in presence of fluoride varnish.

Resumo O objetivo foi avaliar a rugosidade superficial e adesão bacteriana no esmalte dental irradiado com lasers de alta intensidade, associados ou não a um verniz fluoretado. Oitenta fragmentos de esmalte foram igualmente divididos em 8 grupos (n= 10). O grupo 1 não recebeu tratamento e o grupo 2 recebeu aplicação de verniz fluoretado a 5%. Os outros grupos foram irradiados com os lasers Er,Cr:YSGG (8,92 J/cm2), Nd:YAG (84,9 J/cm2) e um laser de diodo (199,04 J/cm2), associados ou não ao verniz fluoretado. A rugosidade superficial foi medida antes e após os tratamentos. Depois, todas as amostras foram imersas em suspensão de S. mutans a 37 °C durante 24 h. As unidades formadoras de colônia (UFC) foram contadas utilizando uma lupa estereoscópica, e os resultados foram expressos em UFC/mm2. Os resultados de rugosidade foram analisados por ANOVA e pelo teste de Tukey, e a adesão bacteriana foi analisada pelo teste de Student (a=5%). As amostras irradiadas sem verniz apresentaram a mesma rugosidade superficial e a mesma adesão bacteriana que as amostras não irradiadas. No entanto, as amostras irradiadas na presença do verniz fluoretado apresentaram maior rugosidade superficial e aderência bacteriana do que as amostras não irradiadas e daquelas irradiadas sem o verniz. A presença de pigmentos no verniz aumentou a ação dos lasers na superfície do esmalte, promovendo a ablação do tecido duro e aumentando significativamente a sua rugosidade superficial. Por isso, a adesão bacteriana no esmalte foi maior quando a irradiação foi realizada na presença do verniz fluoretado.

Influence of biofilm formation on the mechanical properties of enamel after treatment with CPP-ACP crème

Abstract: The study aimed to investigate the effects of bacterial biofilms on changes in the surface microhardness of enamel treated with casein phosphopeptide—amorphous calcium phosphate (CPP-ACP) with and without fluoride. Human enamel blocks with incipient caries-like lesions were divided into four groups of 13: G1: Saliva (Control); G2: fluoride dentifrice (Crest™, 1100 ppm as NaF); G3: CPP-ACP (MI Paste; Recaldent™); and G4: CPP-ACPF (MI Paste Plus; Recaldent™ 900 ppm as NaF). The specimens were soaked in demineralizing solution for 6 h and remineralized in artificial saliva for 18 h alternately for 10 days. The dentifrice was prepared with deionized water in a 1 : 3 ratio (w/w) or applied undiluted in the case of the CPP-ACP group. The surface microhardness (SMH) was evaluated at baseline, after artificial caries, after pH cycling and treatment with dentifrices, and after incubation in media with Streptococcus mutans for biofilm formation. The biofilms were exposed once a day to 2% sucrose and the biofilm viability was measured by MTT reduction. The percentage of change in surface microhardness (%SMHC) was calculated for each block. The data were analyzed by nonparametric test comparisons (α = 0.05). The %SMHC values observed in G2 were different from those of G1, G3, and G4 (p < 0.05). After biofilm formation, %SMHC was positive in G2 and G4 when compared to G1 and G3, but resistance to demineralization after biofilm formation was similar in all groups. In conclusion, the presence of biofilms did not influence the treatment outcomes of anticaries products.

The influence of Brazilian plant extracts on Streptococcus mutans biofilm

Nineteen plant extracts obtained from plants from the Brazilian Amazon showed activity against planktonic Streptococcus mutans, an important bacterium involved in the first steps of biofilm formation and the subsequent initiation of several oral diseases. Objective: Our goal was to verify whether plant extracts that showed activity against planktonic S. mutans could prevent the organization of or even disrupt a single-species biofilm made by the same bacteria. Material and Methods: Plant extracts were tested on a single-bacteria biofilm prepared using the Zürich method. Each plant extract was tested at a concentration 5 times higher than its minimum inhibitory concentration (MIC). Discs of hydroxyapatite were submersed overnight in brain-heart infusion broth enriched with saccharose 5%, which provided sufficient time for biofilm formation. The discs were then submersed in extract solutions for one minute, three times per day, for two subsequent days. The discs were then washed with saline three times, at ten seconds each, after each treatment. Supports were allowed to remain in the enriched medium for one additional night. At the end of the process, the bacteria were removed from the discs by vortexing and were counted. Results: Only two of 19 plant extracts showed activity in the present assay: EB1779, obtained from Dioscorea altissima, and EB1673, obtained from Annona hypoglauca. Although the antibacterial activity of the plant extracts was first observed against planktonic S. mutans, influence over biofilm formation was not necessarily observed in the biofilm model. The present results motivate us to find new natural products to be used in dentistry. .

Are self-ligating brackets related to less formation of Streptococcus mutans colonies? A systematic review

OBJECTIVE: To verify, by means of a systematic review, whether the design of brackets (conventional or self-ligating) influences adhesion and formation of Streptococcus mutans colonies. METHODS: Search strategy: four databases (Cochrane Central Register of Controlled Trials, Ovid ALL EMB Reviews, PubMed and BIREME) were selected to search relevant articles covering the period from January 1965 to December 2012. Selection Criteria: in first consensus by reading the title and abstract. The full text was obtained from publications that met the inclusion criteria. Data collection and analysis: Two reviewers independently extracted data using the keywords: conventional, self-ligating, biofilm, Streptococcus mutans, and systematic review; and independently evaluated the quality of the studies. In case of divergence, the technique of consensus was adopted. RESULTS: The search strategy resulted in 1,401 articles. The classification of scientific relevance revealed the high quality of the 6 eligible articles of which outcomes were not unanimous in reporting not only the influence of the design of the brackets (conventional or self-ligating) over adhesion and formation of colonies of Streptococcus mutans, but also that other factors such as the quality of the bracket type, the level of individual oral hygiene, bonding and age may have greater influence. Statistical analysis was not feasible because of the heterogeneous methodological design. CONCLUSIONS: Within the limitations of this study, it was concluded that there is no evidence for a possible influence of the design of the brackets (conventional or self-ligating) over colony formation and adhesion of Streptococcus mutans. .

OBJETIVO: verificar, por meio de uma revisão sistemática, se o design dos braquetes (convencionais ou autoligáveis) apresenta influência na aderência e formação de colônias de Streptococcus mutans. MÉTODOS: quatro bases de dados (Cochrane Central Register of Controlled Trials; Ovid ALL EMB Reviews; PubMed e BIREME) foram selecionadas para a busca por artigos relevantes, do período de janeiro de 1965 a dezembro de 2012. Os critérios de seleção foram inicialmente aplicados aos títulos e abstracts e o texto integral foi obtido de publicações que cumprira os critérios de inclusão. Dois revisores, de forma independente, extraíram os dados utilizando as palavras-chave "convencionais", "autoligados", "biofilme", "Streptococcus mutans" e "revisão sistemática" e avaliaram a qualidade metodológica dos estudos incluídos. No caso de divergência, foi adotada a técnica do consenso. RESULTADOS: a estratégia de busca resultou em 1.401 artigos. A classificação da relevância científica revelou alta qualidade dos 6 artigos elegíveis, cujos desfechos não foram unânimes em relatar a influência do design dos braquetes (convencionais ou autoligáveis) sobre a aderência e a formação de colônias de Streptococcus mutans, e que outros fatores como características dos tipos de braquetes, o nível de higiene bucal individual, colagem e idade dos indivíduos, podem ter maior influência. O tratamento estatístico foi inviável por causa do desenho metodológico heterogêneo. CONCLUSÕES: dentro das limitações do presente estudo, concluiu-se que não há evidência de uma possível influência do design dos braquetes (convencionais ou autoligáveis) sobre a aderência e a formação ...

Analysis by confocal laser scanning microscopy of the MDPB bactericidal effect on S. mutans biofilm CLSM analysis of MDPB bactericidal effect on biofilm

Since bacteria remain in the dentin following caries removal, restorative materials with antibacterial properties are desirable to help maintaining the residual microorganisms inactive. The adhesive system Clearfil Protect Bond (PB) contains the antibacterial monomer 12-methacryloyloxydodecylpyridinium bromide (MDPB) in its primer, which has shown antimicrobial activity. However, its bactericidal effect against biofilm on the dentin has been little investigated. Objective: The aim of this study was to analyze by confocal laser scanning microscopy (CLSM) and viable bacteria counting (CFU) the MDPB bactericidal effect against S. mutans biofilm on the dentin surface. Material and methods: Bovine dentin surfaces were obtained and subjected to S. mutans biofilm formation in BHI broth supplemented with 1% (w/v) sucrose for 18 h. Samples were divided into three groups, according to the primer application (n=3): Clearfil Protect Bond (PB), Clearfil SE Bond, which does not contain MDPB, (SE) and saline (control group). After the biofilm formation, Live/ Dead stain was applied directly to the surface of each sample. Next, 10 µL of each primer were applied on the samples during 590 s for the real-time CLSM analysis. The experiment was conducted in triplicate. The primers and saline were also applied on the other dentin samples during 20, 90, 300 and 590 s (n=9 for each group and period evaluated) and the CFU were assessed by colonies counting. Results: The results of the CLSM showed that with the Se application, although non-viable bacteria were detected at 20 s, there was no increase in their count during 590 s. In contrast, after the PB application there was a gradual increase of non-viable bacteria over 590 s. Conclusions: The quantitative analysis demonstrated a significant decrease of S. mutans CFU at 90 s PB exposure and only after 300 s of Se application. Protect Bond showed an earlier antibacterial effect than Se Bond.

The effect of iron on Streptococcus mutans biofilm and on enamel demineralization

Iron (Fe) may have an anticaries effect by specific inhibition of glycosyltransferase (GTF) enzymes of Streptococcus mutans, but this hypothesis has not yet been clarified. In this study, S. mutans biofilms were formed on blocks of bovine dental enamel of a predetermined surface hardness (SH). These biofilms were exposed eight times/day to 10% sucrose, and two times/day they were subjected to one of the following treatments: G1, 0.9% NaCl as a negative control; G2, 0.12% chlorhexidine digluconate (CHX) as a positive antibacterial control; G3, 0.05% NaF (225 ppm F) as a positive anticaries control; G4, G5, and G6, ferrous sulfate (Fe2+) at concentrations of 1.0, 10.0, and 100.0 µg Fe/mL, respectively. The experiment was performed in triplicate and was repeated three times (n = 9). The pH of the culture medium was determined every 24 h as an indicator of the biofilm's acidogenicity. The biofilm formed on each block was collected for determination of the viable bacteria and concentration of extracellular polysaccharides (EPS). Enamel SH was again determined and the percentage of SH loss (%SHL) was calculated as an indicator of demineralization. Iron treatment reduced the number of viable bacteria formed in the S. mutans biofilm (p = 0.04), in a dose-dependent manner, and also reduced the enamel's %SHL (p = 0.005). At 100 µg/mL, Fe reduced enamel demineralization as effectively as CHX and NaF (p < 0.05), but it did not inhibit EPS production. In conclusion, the data suggest that the anticaries mechanism of action of Fe may not involve the oxidative inhibition of GTFs.

Hydrophobicity test in mutans Streptococci

Kinetic hydrophobic measurements were performed by confronting 40 mutans streptococci from thirty 10- to 20-year-old patients with 200 ml hexadecane (Sigma). Fourteen patients had high dental caries risk (Group A), dmft + DMFT >5 with 3 or more active caries, and 16 had low dental caries risk (Group B), dmft + DMFT <3 without active caries. Twenty bacteria from Group A and 20 bacteria from Group B were typed using De La Higuera's procedure and confirmed by API strip (bio- Merieux). From the 14 patients in Group A we obtained 12 S. mutans (8 hydrophobic/ 4 non-hydrophobic), 5 S. sobrinus (4 hydrophobic/ 1 non-hydrophobic) and 3 S. rattus (hydrophobic). From the 16 patients in Group B we obtained 11 Streptococcus mutans (10 non-hydrophobic/ 1 hydrophobic), 7 Streptococcus sobrinus (6 non-hydrophobic/ 1 hydrophobic) and 2 Streptococcus rattus (hydrophobic). Patients with high dental caries risk have a higher prevalence of hydrophobic bacteria than patients with low dental caries risk (p=0.0003). All typed S. rattus were hydrophobic.

Con el objeto de evaluar una posible relacion entre hidrofobicidad y caries dental, se estudiaron 40 cepas de Streptococcus grupo mutans provenientes de 30 pacientes de entre 10 y 20 anos, 14 pacientes con tres o mas caries activas e indice ceod mas CPOD > 5 (Grupo A) y 16 pacientes sin caries activas, con ceod mas CPOD < 3 (Grupo B). Las cepas fueron aisladas a partir de muestras de saliva en AMS-BT y tipificadas por pruebas bioquimicas y API-strep realizandose la medicion cinetica de hidrofobicidad, enfrentandolas con 200 ml de hexadecano (Sigma). En el grupo A se caracterizaron 12 cepas Streptococcus mutans: 8 hidrofobicas y 4 no hidrofobicas, 5 cepas de Streptococcus sobrinus: 4 hidrofobicas y 1 no hidrofobica y 3 cepas Streptococcus rattus hidrofobicas. En el grupo B, se caracterizaron 11 cepas de S. mutans, 10 no hidrofobicas y 1 hidrofobica, 7 cepas de S. sobrinus: 6 no hidrofobicas y 1 hidrofobica y 2 cepas de S. rattus hidrofobicas. Todos los pacientes del grupo A presentaron al menos 1 cepa hidrofobica. En las cepas aisladas de estos pacientes se demostro la existencia de una alta prevalencia de Streptococcus grupo mutans con caracteristicas hidrofobicas p=0,0003. Estos resultados indicarian la relacion entre la capacidad de adherencia a hexadecano y caries activa. Todas las cepas tipificadas como S. rattus fueron hidrofobicas independientemente del grupo de origen.

Nanotechnology: Role in dental biofilms.

Biofilms are surface- adherent populations of microorganisms consisting of cells, water and extracellular matrix material Nanotechnology is promising field of science which can guide our understanding of the role of interspecies interaction in the development of biofilm. Streptococcus mutans with other species of bacteria has been known to form dental biofilm. The correlation between genetically modified bacteria Streptococcus mutans and nanoscale morphology has been assessed using AFMi.e atomic force microscopy. Nanotechnology application includes 16 O/ 18 O reverse proteolytic labeling,use of quantum dots for labeling of bacterial cells, selective removal of cariogenic bacteria while preserving the normal oral flora and silver antimicrobial nanotechnology against pathogens associated with biofilms. The future comprises a mouthwash full of smart nanomachines which can allow the harmless flora of mouth to flourish in a healthy ecosystem

Clinical status and detection of periodontopathogens and Streptococcus mutans in children with high levels of supragingival biofilm

Knowledge about the presence of some important oral pathogens is an important step in better identifying children at risk for periodontal and/or caries diseases in later life. The purpose of this study was to detect the presence of Streptococcus mutans (Sm), Aggregatibacter actinomycetemcomitans (Aa), Campylobacter rectus (Cr), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), and Tannerella forsythia (Tf) in gingival biofilm samples from 196 children, and to assess whether any of these pathogens are more associated with gingival inflammation extension and the Decayed/Missing/Filled teeth (DMFT/dmft) index. The subjects presented plaque index greater than 80 percent and were divided in 3 groups according to the bleeding index (BI): I) Low bleeding (< 30 percent), II) Medium bleeding (31 - 59 percent) and III) High bleeding (> 60 percent). The presence of each pathogen was determined by PCR. The prevalence of Sm was 71.9 percent and the mean dmft/DMFT was 6.68. The prevalence in low, medium and high bleeding groups was 43.5 percent, 34.5 percent and 46.7 percent for Aa; 43.5 percent, 37.9 percent, and 36.7 percent for Cr; 99.1 percent, 100 percent, and 96.7 percent for Pg; 56.5 percent, 56.9 percent, and 66.7 percent for Pi; and 58.3 percent, 60.3 percent, and 56.7 percent for Tf, respectively. Pg (99.0 percent) was the most prevalent periodontal pathogen detected followed by Tf (58.7 percent), Pi (58.2 percent), Aa (41.3 percent) and Cr (40.8 percent). Our study indicated that in this high plaque index population studied, a high prevalence of Sm and high mean DMFT were observed. In addition, the presence of Pi was associated with the presence of inflammation (P < 0.05) whereas Cr was associated with periodontal health (P < 0.05).

Knowledge and attitude of parents or caretakers regarding transmissibility os caries disease

Dental caries is a transmissible infectious disease in which mutans streptococci are generally considered to be the main etiological agents. Although the transmissibility of dental caries is relatively well established in the literature, little is known whether information regarding this issue is correctly provided to the population. The present study aimed at evaluating, by means of a questionnaire, the knowledge and usual attitude of 640 parents and caretakers regarding the transmissibility of caries disease. Most interviewed adults did not know the concept of dental caries being an infectious and transmissible disease, and reported the habit of blowing and tasting food, sharing utensils and kissing the children on their mouth. 372 (58.1 percent) adults reported that their children had already been seen by a dentist, 264 (41.3 percent) answered that their children had never gone to a dentist, and 4 (0.6 percent) did not know. When the adults were asked whether their children had already had dental caries, 107 (16.7 percent) answered yes, 489 (76.4 percent) answered no, and 44 (6.9 percent) did not know. Taken together, these data reinforce the need to provide the population with some important information regarding the transmission of dental caries in order to facilitate a more comprehensive approach towards the prevention of the disease.

Influência de um polidor resinoso na adesão de Streptococcus mutans in situ / Resinous polisher influence over in situ adhesion of Streptococcus mutans

A placa bacteriana é um biofime específico formado sobre tecidos orais, materiais restauradores, aparatos ortodônticos ou qualquer outra superfície na cavidade bucal. Entre diversos fatores a rugosidade das superfícies é de relevância crítica na qual os procedimentos de acabamento e polimento apresentam um papel vital na dentística restauradora. O objetivo deste trabalho foi de avaliar os níveis de rugosidade de quatro materiais restauradores dentais diferentes submetidos a três tipos de tratamento superficial (compressão por matriz mylar - grupo controle negativo, acabamento com pontas diamantadas de granulação fina - grupo controle positivo e aplicação de polidor resinoso BisCover™ (Bisco) depois do acabamento com as pontas diamantadas) e a influência sobre a colonização por Streptococcus mutans no biofilme inicial. Os materiais analisados foram: um cimento de ionômero de vidro convencional (Ionofil® / Voco), um cimento de ionômero de vidro modificado por resina (Vitremer™ / 3M ESPE), um compósito nano-particulado (Filtek Supreme™ / 3M ESPE) e um compósito nano-híbrido (Grandio® / Voco). A rugosidade foi medida por um instrumento de escaneamento 3-D (TalyScan 150 / Taylor Hobson) e a avaliação quantitativa de S. mutans no biofilme inicial foi realizada in vivo através da extração do biofilme dental (formado sobre discos fixados sobre moldeiras individuais usadas por um voluntário por um período de 24 horas). Um total de oito discos de cada material em cada grupo de tratamento superficial foi feito para o ensaio microbiológico e da mesma forma cinco discos foram feitos para cada situação para a mensuração da rugosidade. Resultados: análise superficial 3-D: o tratamento superficial e o tipo de material afetaram significativamente os valores de Ra e Rz (P<0.05)...

Dental plaque is a specific biofilm formed over oral tissues, restorative materials, orthodontic apparatus or any other surface in oral cavity. Among several factors, the roughness of surfaces is one of critical relevance in which finishing and polishing procedures play a vital role in restorative dentistry. The aim of this work was to evaluate the roughness levels of four different restorative dental materials submitted to three kinds of superficial treatment (compression with mylar matrix - negative control group, finishing with fine grain diamond points - positive control group and application of a resin polisher BisCover™ (Bisco) after finishing with the diamond points) and the influence on Streptococcus mutans colonization in initial biofilm. The materials analyzed were: one conventional glass ionomer cement (Ionofil® / Voco), one resin modified glass ionomer cement (Vitremer™ / 3M ESPE), one nano-filled composite resin (Filtek Supreme™ / 3M ESPE) and one nano-hybrid composite resin (Grandio® / Voco). The roughness was measured with a 3-D scanning instrument (TalyScan 150 / Taylor Hobson ) and the quantitative evaluation of S. mutans in initial biofilm was performed in vivo through dental biofilm extraction (developed over discs fixed on custom-fitted trays wore by one volunteer for a 24 hours period). A total of eight discs of each material in each superficial treatment group were made for the microbiological assay and in the same way five discs were made for each situation for the roughness measurement. Results: 3-D surface analyses: the surface treatment and the type of material significantly affected the Ra and the Rz values (P<0.05)...

Confocal laser scanning microscopic analysis of the depth of dentin caries-like lesions in primary and permanent teeth

This study analyzed comparatively, by confocal laser scanning microscopy (CLSM), the depth of caries-like lesions produced by biological and chemical artificial models in permanent and primary dentin. Six primary molars and six premolars were used. The occlusal enamel was removed and a nail polish layer was applied on the specimens, except for a 4 x 2 mm area on dentin surface. Half of specimens were immersed in acid gel for 14 days (chemical model) and the other half was immersed in BHI broth with S. mutans for 14 days (biological model). After development of artificial caries, the crowns were longitudinally sectioned on the center of the carious lesion. Three measurements of carious dentin depth were made in each specimen by CLSM. Measurements depths were compared between the caries models and between tooth types by one-way ANOVA and Tukey test (a=5 percent). For permanent teeth, the biological model showed significantly higher (p<0.05) caries depth values than the chemical model. For primary teeth, no statistically significant difference (p>0.05) was found between the caries models. The artificial caries model influenced caries depth only in permanent teeth. There was no difference in carious dentin depth between permanent and primary teeth, regardless of the artificial caries model.

O objetivo deste estudo foi comparar a profundidade de cárie produzida em dentina permanente e decídua por modelos biológico e químico de produção artificial de cárie utilizando o microscópio confocal de varredura a laser (CLSM, na sigla em Inglês). Seis molares decíduos e seis pré-molares foram usados. O esmalte oclusal foi removido expondo a dentina subjacente. A seguir, um verniz de unha foi aplicado em toda a amostra, exceto em uma área de 4 x 2 mm na superfície dentinária. Metade das amostras foi imersa em gel ácido por 14 dias (modelo químico) e a outra metade imersa em BHI com S. mutans por 14 dias (modelo biológico). Após o desenvolvimento da cárie artificial, as coroas foram seccionadas longitudinalmente no centro da lesão de cárie. Três medidas da profundidade de cárie produzida foram realizadas ao longo de cada espécime e analisadas em CLSM. As medidas da profundidade de cárie entre os modelos e entre os tipos de dentes foram analisadas pelo teste de ANOVA a um critério e teste de Tukey (p<0,05). Para os dentes permanentes, o modelo biológico mostrou maiores valores de profundidade de cárie quando comparado ao modelo químico. Entretanto, para os dentes decíduos não houve diferença estatisticamente significante na profundidade de cárie entre os modelos. Desta forma, o modelo de produção de cárie artificial influenciou a profundidade de cárie apenas para os dentes permanentes, não existindo diferença na profundidade de cárie entre dentes decíduos e permanentes, independente do modelo de cárie utilizado.

Knowledge and attitude on infant oral health among graduating medical students in Kerala.

Providing dental and oral health care to all children in Kerala remains a thorny challenge. Lack of community water fluoridation, dental workforce shortages and geographical barriers all aggravate oral health and access problems. Children from low-income and minority families and children with special needs are at particular risk. Family centered disease prevention strategies are needed to reduce oral health disparities in children. Oral health promotion can take place in a primary care practitioner's office, but medical providers often lack relevant training. Present study was conducted to evaluate knowledge and attitude of graduating medical students towards infant oral health qualitative methods were used to evaluate the program.

Adhesion of Streptococcus mutans to salivary proteins in caries-free and caries susceptible individuals

La adhesión de los microorganismos a las superficies dentales, es el paso inicial en la formación de la placa dentobacteriana, Streptococcus mutans (S. mutans) es uno de los encontrados en ésta y está asociado como el principal agente causal de una delas enfermedades más comunes en los humanos, la caries dental. La adherencia de esta bacteria se da por la interacción de adhesinas que la constituyen con los componentes salivales, específicamente con los que están formando parte de la película adquirida. La complejidad de esta interacción ha sido motivo deestudio durante los últimos años, hasta el punto de identificar algunos componentes salivales relacionados con la unión a las superficies del esmalte, tales como Proteínas ricas en prolina(PRPs), staterinas,Histatinas,Cistatinas, etc. En el presente trabajo se buscó determinar la capacidad de adhesión de S. mutans a hidroxilapatita sintética incubada con muestras de salivade personas con y sin experiencia de caries. Para estos ensayos se utilizó tanto la muestra de saliva completa como extractos de proteínas salivales, obtenidos por medio de la separaciónde las proteínas contenidas en la muestra por SDS-PAGE, en tres rangos de peso molecular seleccionados de acuerdo con el perfil electroforético que fue comúnmente encontrado. Losresultados indican que la adhesión de este microorganismo es mayor en las personas sin experiencia de caries cuando se ensayó con saliva completa y con las proteínas separadas en el rangode peso molecular de 120-159 kDa. Sugiriendo que la adhesión por sí sola no tiene un efecto determinante en los mecanismos que producen la enfermedad en algunas personas. Sin embargo estos hallazgos son interesantes ya que pueden contribuir en el diseño de estrategias para intervenir en la adhesión de S. mutanssobre las superficies dentales

Adhesion of microorganisms to dental surfaces is the initial step in the formation of dental bacterial plaque. Streptococcus mutans (S. mutans) is considered the main causal agent of one of the most common diseases in humans: dental caries. Adherence of these bacteria results from the interaction of adhesins that form part of their structure with salivary components, specifically those that compose the acquired pellicle. The complexity of this interaction has been the subject of studies in past years, to the extent of identifying certain salivary components related to adhesion to enamel surfaces, such as proline-rich proteins (PRSs), Staherins, Histatins, Cystatins, etc. One of the objectives of this study was to determine the adhesion capacity of S. mutans to synthetic hydroxyapatite incubated with saliva samples of caries-active and caries-inactive individuals. For the purpose of these assays, both the whole saliva samples and the salivary protein extracts were used. They were obtained by separating the proteins contained in the simple SDS-PAGE, in three ranges of molecular weight, selected in accordance with the electrophoresis profile that was usually found. The results indicated that the adhesion of this microorganism was greater in caries-inactive patients, when tested with whole saliva and proteins in the 120-159 kDa molecular weight range. This suggests that adhesion, per se, does not have a definite effect on the mechanisms that cause the disease in some individuals. However, these are interesting findings that may contribute to the design of strategies to control the adhesion of S. mutans to the tooth’s surface.