Serotipos prevalentes de Streptococcus mutans en América Latina / Prevalent serotypes of Streptococcus mutans in Latin America

La microbiota oral está conformada por diversas especies bacterianas que en condiciones normales desempeñan una función protectora del huésped; sin embargo, cuando existe un desequilibrio en el ecosistema, estos microorganismos son capaces de producir diversas manifestaciones como lo es el caso de la caries dental, enfermedad infecciosa producida principalmente por Streptococcus mutans, patógeno capaz de desmineralizar los tejidos duros del diente mediante la fermentación de hidratos de carbono obtenidos de la dieta. Se ha identificado en la pared celular de este microorganismo ocho serotipos que intervienen en la adhesión, agregación y coagregación bacteriana. En los seres humanos S. mutans presenta los serotipos c, e y f, siendo el serotipo c el más prevalente a nivel mundial, el cual se conoce que está asociado a pacientes sanos, a diferencia del e y f que son capaces de invadir las células endoteliales de las arterias coronarias. No obstante, en los últimos años se ha logrado identificar el serotipo k que de igual manera presenta alta capacidad de invadir el endotelio humano, actuando en la patogénesis de las enfermedades cardiovasculares. El objetivo de la presente revisión bibliográfica es lograr cuantificar los serotipos prevalentes de S. mutans en América Latina (AU)

The oral microbiota is made up of various bacterial species that under normal conditions perform a protective function of the host, however, when there is an imbalance in the ecosystem, these microorganisms are capable of producing various manifestations such as caries, an infectious disease. produced mainly by Streptococcus mutans, a pathogen capable of demineralizing the hard tissues of the tooth through the fermentation of carbohydrates obtained from the diet. Eight serotypes involved in bacterial adhesion, aggregation and coaggregation have been identified in the cell wall of this microorganism. In humans, S. mutans presents serotypes c, e, and f, serotype c being the most prevalent worldwide, which is known to be associated with healthy patients, unlike e and f, which are capable of invading the endothelial cells of the coronary arteries. However, in recent years it has been possible to identify serotype k, which also has a high capacity to invade the human endothelium, acting in the pathogenesis of cardiovascular diseases. The objective of this literature review is to quantify the prevalent serotypes of S. mutans in Latin America (AU)

Nicotine is a potent extracellular polysaccharide inducer in Fusobacterium nucleatum biofilms

The purpose of this in vitro study was to analyze the influence of nicotine on the extracellular polysaccharides in Fusobacterium nucleatum biofilm. Methods: F. nucleatum (ATCC 10953) biofilms supplemented with different concentrations of nicotine (0, 0.5, 1, 2, 4, and 8 mg/mL) were grown in two different BHI broth conditions [no sucrose and 1% sucrose]. Extracellular polysaccharides assay, pH measurements, and a spectrophotometric assay were performed. Data were submitted for ANOVA and Tukey honestly significant difference analyses (HSD) tests (α =.05). Results: Extracellular polysaccharides synthesis was influenced by an interaction between nicotine concentrations and growth medium solution containing sucrose (P<.05). The pH values declined in the sucrose-exposed biofilm were greater than in the group exposed only to nicotine (P<.05). The biofilm exposed to sucrose and nicotine had a higher total biofilm growth (P<.05) than the nicotine-treated biofilm without sucrose. Conclusions: Regardless of sucrose exposure, biofilms exposed to different nicotine concentrations influenced the amount of extracellular polysaccharides

Construction of a caries diagnosis model based on microbiome novelty score / 华西口腔医学杂志

OBJECTIVES@#This study aimed to analyze the bacteria in dental caries and establish an optimized dental-ca-ries diagnosis model based on 16S ribosomal RNA (rRNA) data of oral flora.@*METHODS@#We searched the public databa-ses of microbiomes including NCBI, MG-RAST, EMBL-EBI, and QIITA and collected data involved in the relevant research on human oral microbiomes worldwide. The samples in the caries dataset (1 703) were compared with healthy ones (20 540) by using the microbial search engine (MSE) to obtain the microbiome novelty score (MNS) and construct a caries diagnosis model based on this index. Nonparametric multivariate ANOVA was used to analyze and compare the impact of different host factors on the oral flora MNS, and the model was optimized by controlling related factors. Finally, the effect of the model was evaluated by receiver operating characteristic (ROC) curve analysis.@*RESULTS@#1) The oral microbiota distribution obviously differed among people with various oral-health statuses, and the species richness and species diversity index decreased. 2) ROC curve was used to evaluate the caries data set, and the area under ROC curve was AUC=0.67. 3) Among the five hosts' factors including caries status, country, age, decayed missing filled tooth (DMFT) indices, and sampling site displayed the strongest effect on MNS of samples (P=0.001). 4) The AUC of the model was 0.87, 0.74, 0.74, and 0.75 in high caries, medium caries, low caries samples in Chinese children, and mixed dental plaque samples after controlling host factors, respectively.@*CONCLUSIONS@#The model based on the analysis of 16S rRNA data of oral flora had good diagnostic efficiency.

Oral microbiota in human systematic diseases / 国际口腔科学杂志·英文版

Oral bacteria directly affect the disease status of dental caries and periodontal diseases. The dynamic oral microbiota cooperates with the host to reflect the information and status of immunity and metabolism through two-way communication along the oral cavity and the systemic organs. The oral cavity is one of the most important interaction windows between the human body and the environment. The microenvironment at different sites in the oral cavity has different microbial compositions and is regulated by complex signaling, hosts, and external environmental factors. These processes may affect or reflect human health because certain health states seem to be related to the composition of oral bacteria, and the destruction of the microbial community is related to systemic diseases. In this review, we discussed emerging and exciting evidence of complex and important connections between the oral microbes and multiple human systemic diseases, and the possible contribution of the oral microorganisms to systemic diseases. This review aims to enhance the interest to oral microbes on the whole human body, and also improve clinician's understanding of the role of oral microbes in systemic diseases. Microbial research in dentistry potentially enhances our knowledge of the pathogenic mechanisms of oral diseases, and at the same time, continuous advances in this frontier field may lead to a tangible impact on human health.

Impacto do uso de probióticos sobre o biofilme bucal / Impact of the use of probiotics on oral biofilme

Objetivo: o objetivo desse estudo foi realizar uma revisão integrativa sobre o impacto do uso de probióticos sobre o biofilme bucal. Revisão de literatura: a busca foi feita nas bases de dados Scielo, Science Direct, PubMed e LILACS, utilizando-se como descritores os termos probióticos, biofilme, cárie e periodontite, nos idiomas português e inglês. Foram selecionados os estudos que delimitavam o assunto em relação ao biofilme bucal. Foram encontrados 1689 artigos e selecionados 48. Os resultados demonstraram empregabilidade otimista dos probióticos, visto que apenas 2 artigos selecionados não obtiveram resultados positivos. Dentre as bactérias probióticas, a Lactobacillus salivarius e a Lactobacillus casei foram as mais utilizadas. Sugerem-se produtos viscosos como meio de utilização, por sua boa substantividade. Considerações finais: Recomenda-se que sejam realizados mais estudos com metodologias comparáveis, para melhor compreensão do efeito dos probióticos no biofilme bucal e para que sejam padronizadas doses, modo de administração, tempo da duração do seu efeito, bem como as cepas e as espécies bacterianas mais eficazes para cada objetivo. Principalmente, compreender melhor o seu mecanismo de ação para que assim possa ser protocolada uma técnica eficiente, fundamentada e segura para sua aplicação.

Objectives: to carry out an integrative review on the impact of the use of probiotics on oral biofilm. Materials and method: the search was done in the databases SciELO, Science Direct, PubMed and LILACS, using the terms probiotics, biofilm, caries and periodontitis, in Portuguese and English. The studies selected were those that delimited the subject in relation to the oral biofilm. Results: a total of 1.689 articles were found and 48 were selected. The results demonstrated optimum employability of probiotics, since only two of the selected articles did not obtain positive results. Among the probiotic bacteria, Lactobacillus salivarius and Lactobacillus casei were the most used. Viscous products are suggested as a means of use because of their good substantivity. Final considerations: it is recommended that further studies be conducted with comparable methodologies to better understand the effect of probiotics on oral biofilm and to standardize doses, mode of administration, duration of their effect, as well as the most effective strains and bacterial species for each objective. Mainly, it is necessary a better understanding of the mechanism of action, so that an efficient, reasoned and safe technique can be defined for its application.(AU)

Caries and genetic variability of streptococcus mutans / Caries y variabilidad genética de streptococcus mutans

In the last two decades, the increase in population genetics studies has contributed to elucidating important questions about the evolution of the pathogenesis of bacteria of clinical interest. The objective of this study is to revise and update the knowledge of the last fifteen years regarding the genetic variability of Streptococcus mutans and their association with dental caries. Streptococcus mutans, one of the most widely distributed bacteria in the world, are heavily associated with this condition. This research shows the results of numerous studies carried out in various countries that, using molecular and biochemical methods, revealed associations between different serotypes and caries activity. In addition, it is reported that the population genetics structure of Streptococcus mutans in Argentina is highly recombinant, which reflects the largest waves of human immigration that occurred in the 19th and 20th centuries. On the other hand, demographic analysis suggests that these bacteria experienced a population expansion that coincided with the beginning of agricultural development.

En las últimas dos décadas el incremento de los estudios de genética de poblaciones ha contribuido a dilucidar cuestiones importantes sobre la evolución de la patogénesis de bacterias de interés clínico. El objetivo de este trabajo es realizar una actualización sobre los conocimientos de los últimos quince años referidos a la variabilidad genética de Streptococcus mutans y su relación con la caries dental. Streptococcus mutans, de amplia distribución mundial, es una de las bacterias más fuertemente asociada a dicha enfermedad. En este trabajo se muestran resultados de numerosos estudios realizados en diferentes países que utilizando métodos moleculares y bioquímicos revelaron asociaciones entre diferentes serotipos y la actividad de caries. Además, se reporta que la estructura genética poblacional de Streptococcus mutans de Argentina es de alto nivel recombinante, lo que reflejaría las grandes oleadas inmigratorias humanas ocurridas en los siglos 19thy 20th. Por otra parte, los análisis demográficos sugieren que esta bacteria experimentó una expansión poblacional coincidente con el comienzo del desarrollo de la agricultura

Actividad antimicrobiana in vitro del Camu Camu (Myrciaria Dubia) contra microorganismos orales: una revisión sistemática / Antimicrobial activity in vitro of Camu-Camu (Myrciaria Dubia) against oral microorganisms: a systematic review

RESUMEN Objetivos. Evaluar la actividad antimicrobiana de la Myrciaria dubia sobre microorganismos orales. Materiales y métodos . Se realizó una revisión sistemática de la literatura siguiendo las recomendaciones PRISMA mediante búsquedas en Pubmed, LILACS, SciELO, ProQuest, EBSCO y Google Scholar, de estudios publicados durante 2008 y 2018. Resultados . Se recopilaron 11 estudios, in vitro, todos los estudios evidenciaron actividad antimicrobiana positiva, principalmente por cada una de las partes de sus frutos, sobre grampositivos. Sin embargo, dicha actividad fue comparada con clorhexidina en solo dos estudios y en otro resultó ser mejor que un antibiótico. Se detectó un alto riesgo de sesgo en la mayoría de estudios. Los compuestos fenólicos incluidos polifenoles y acilfloroglucinoles fueron señalados como los responsables de su actividad. Conclusiones . Existe evidencia sobre la actividad antimicrobiana de M. dubia. Su estudio como antimicrobiano contra microorganismos orales es aún incipiente, pero se advierte un gran potencial debido a los fitoquímicos potentes que posee. Además, se necesita más estudios de calidad, que comparen su actividad versus antisépticos orales y sobre más microorganismos asociados a caries dental y enfermedad periodontal.

ABSTRACT Objectives. To evaluate the antimicrobial activity of Myrciaria dubia on oral microorganisms. Materials and Methods. A systematic review of the literature following PRISMA guidelines was conducted through searches of studies published between 2008 and 2018 in Pubmed, LILACS, SciELO, ProQuest, EBSCO, and Google Scholar. Results. Eleven (11) in vitro studies were gathered; all the studies showed positive antimicrobial activity on gram-positives, mainly by each of the parts of its fruits. However, such activity compared to chlorhexidine in only two studies, and, in another study, it was better than an antibiotic. A high risk of bias was detected in most studies. Phenolic compounds, including polyphenols and acylphloroglucinols, were identified as responsible for its activity. Conclusions. There is evidence of antimicrobial activity in M. dubia. Its study as an antimicrobial against oral microorganisms is still incipient, but there is great potential thanks to the potent phytochemicals it contains. Also, additional quality studies are required: comparing their activity versus oral antiseptics and on microorganisms associated with dental caries and periodontal disease.

Validation of an adherence assay to detect group mutans streptococci in saliva samples / Validación del Test de adherencia para el recuento de estreptococcos del grupo mutans en muestras de saliva

The aim of the present study was to validate and establish a cut off point and the predictive value of an adhesion test (AA-MSMG), as a microbiological method for evaluating cariogenic risk. The study is based on a variant (20% sucrose) of a selective medium descripted by Gold et al. (MSMG). This method differentiates mutans group streptococci (MGS) by exacerbating the production of insoluble extracellular polysaccharide which gives adhesion to surfaces such as glass, plastic and dental enamel. Caries assessment according to ICDAS was conducted in 154 patients (aged >21 years) who were attended at Preventive and Community Dentistry Department, School of Dentistry, University of Buenos Aires, Argentina, between August 2017 to August 2018. The study population was assigned to groups according to the presence/ absence of caries lesions: Group A: ICDAS lesion code = 0 (L=0) on all dental surfaces (n=23); and Group B: L>1 (n=131). After mouth-rinsing with distilled water, saliva samples were collected with fasting and hygiene protocol, and sent immediately to the Microbiological Diagnosis Laboratory, Microbiology Department, School of Dentistry, University of Buenos Aires. Samples were homogenized and serially diluted to the tenth. 100 pl of the dilutions were cultured in 25 cm² sterile plastic flasks containing 9.9 ml of modified selective medium described by Gold (MSMG-selective and differential medium). Cultures were incubated in an anaerobic atmosphere at 36 ± 1°C for 48 hours. The supernatants were eluted and the samples washed with sterile distilled water. Colony forming unit counts were performed by calibrated researchers (Kappa >0.75) using a stereoscopic microscope at 50X. Mutans group streptococci (MGS) counts ranged from 1x10(4) to 1x10(5) CFU/ml in group A, and were higher than 1x10(6) CFU/ml in Group B. Statically analysis of results (ROC) showed that the AAMSMG has a satisfactory predictive value (91%) and established a cutoff point in 1.68x10(5) UFC / ml. This would indicate that individuals whose MGS saliva counts are higher than the cutoff value would be 5 times more likely to develop dental caries. Adherence assay could be a useful microbiological predictor of caries risk.

El objetivo del presente estudio fue validar, establecer el punto de corte y valor predictivo de una técnica microbiológica para evaluar el nivel de estreptococos del grupo mutans en saliva. La técnica consiste en un test de adherencia que emplea un medio selectivo modificado (20% sacarosa) descripto por Gold et al. (TA-MSMG). Este método permite diferenciar a los estreptococos del grupo mutans (SGM) exacerbando la producción del polisacárido extracelular insoluble que le confiere adhesión a superficies como vidrio, plástico y esmalte dental. De acuerdo con los criterios de ICDAS se sembraron 154 salivas de pacientes mayores de edad, que asistieron al Servicio de Odontología Preventiva y Comunitaria de la Facultad de Odontología de la Universidad de Buenos Aires entre los meses de agosto de los años 2017 y 2018. La población estudiada fue asignada a dos grupos según la presencia / ausencia de lesiones de caries: Grupo A: código de lesión ICDAS = 0 (L = 0) en todas las superficies dentales (n = 23); y Grupo B: L> 1 (n = 131). Después de realizar un enjuague bucal con agua destilada, las muestras de saliva se recogieron según protocolo (ayuno de 4 horas y suspensión de higiene dental de 12 hs). Las muestras se remitieron de inmediato al Laboratorio de Diagnóstico Microbiológico, Departamento de Microbiología de la Facultad de Odontología, Universidad de Buenos Aires. Para su procesamiento, las muestras fueron homogeneizadas y diluidas al décimo. Se cultivaron 100 pl de las diluciones en botellas de plástico estériles de 25 cm² que contenían 9,9 ml de medio de Gold modificado (MSMG-20% sacarosa). Los cultivos se incubaron en atmósfera anaeróbica a 36 ± 1°C durante 48 horas. El sobrenadante se eluyó y las muestras se lavaron con agua destilada estéril. Los recuentos de unidades formadoras de colonias SGMfueron realizados por investigadores calibrados (Kappa >0.75) utilizando un microscopio estereoscópico a 50X. Los recuentos de SGM presentaron una variación entre 1x10(4)y 1x10(5) UFC/ml en el grupo A, mientras que en el Grupo B fueron superiores a 1x10(6) UFC/ml. El análisis estadístico de los resultados determinó una curva ROC que establece para el TA-MSMG un valor predictivo del 91% y un punto de corte en 1.68x10(5) UFC SGM / ml. Esto indicaría que los individuos cuyos recuentos en saliva de SGM sean superiores al valor de corte, tendrían 5 veces más posibilidades de desarrollar caries (5:1). Este método podría ser un instrumento útil al momento de evaluar (indicador microbiológico) el riesgo cariogénico del paciente.

Serão as bactérias cariogénicas o fator de risco maior para cáries dentárias em doentes com retocolite ulcerativa? / Are cariogenic bacteria the major risk factor to dental caries in patients with ulcerative colitis?

ABSTRACT BACKGROUND: High prevalence of dental caries in ulcerative colitis (UC) has been attributed to diet and changes in salivary environment. OBJECTIVE: We aimed to characterize the prevalence of dental caries, salivary flow rates, salivary buffering capacity and cariogenic bacteria counts of Mutans streptococci and Lactobacillus spp and to evaluate their relationship with drug therapy, disease activity and duration. METHODS: A cross-sectional study was performed with UC patients followed in a tertiary center. Participants were submitted to a questionnaire (including demographic data, oral hygiene, eating habits) and a clinical observation with assessment of plaque index and Decayed, Missing and Filled Teeth index. Unstimulated/stimulated saliva was collected. Medical records, disease activity (Partial Mayo Score) and disease duration were collected. Laboratory data included salivary flow rates, salivary buffering capacity (CRT® buffer) and cariogenic bacteria count (Mutans streptococci and Lactobacillus spp) in saliva using the CRT® bacteria test (results: high or low counts). RESULTS: Thirty UC patients were recruited. Oral hygiene routines were daily teeth brushing once or more (96.7%) and fluoride toothpaste (73.3%). Decayed, Missing and Filled Teeth index (mean 16.17±6.428) was not affected by the frequency of soft drinks, cakes, sweets and sugars between meals (P>0.2). Long-term disease showed a trend towards higher prevalence of caries (P=0.06). Most presented normal salivary flow rates, unstimulated (73.3%) and stimulated (60.0%), and high salivary buffering capacity (66.7%). Any association was found with age, gender, disease activity, disease duration and drug therapy. High Mutans streptococci and low Lactobacillus spp count were observed in 73.3% and 60% of patients, respectively. Patients with active disease (100%) and longer duration (88.9%) displayed higher Mutans streptococci count. CONCLUSION: The prevalence of dental caries observed in UC patients was significant and did not seem to be influenced by their eating habits. The high prevalence of Mutans streptococci count may be a major risk factor for dental caries and may be looked as part of the UC dysbiosis. Dental care of UC patients should be planned according with this microbiota variation.

RESUMO CONTEXTO: Uma elevada prevalência de cáries dentárias em doentes com retocolite ulcerativa (RCU) tem sido atribuída à dieta e alterações no ambiente salivar. OBJETIVO: Este estudo pretende caracterizar a prevalência de cáries dentárias, taxas de fluxo salivar, capacidade de tamponamento da saliva e contagem de bactérias cariogénicas, Streptococcus mutans e Lactobacillus spp e avaliar a sua relação com a terapêutica farmacológica e a atividade e duração da doença. MÉTODOS: Estudo transversal com doentes com RCU seguidos num centro terciário. Os participantes foram submetidos a um questionário (incluindo questões sobre dados sociodemográficos, higiene oral e hábitos alimentares), e a uma observação clínica com avaliação do índice de placa e índice Decayed, Missing and Filled Teeth. Amostras de saliva não estimulada e estimulada foram colhidas. Os registos clínicos, a atividade da doença (score parcial de Mayo) e a sua duração foram avaliados. Os dados laboratoriais incluíram taxas de fluxo salivar, capacidade de tamponamento da saliva (CRT® buffer) e a contagem de bactérias cariogénicas (Streptococcus mutans e Lactobacillus spp) utilizando o teste CRT® (resultado: contagem elevada ou reduzida). RESULTADOS: Foram recrutados 30 doentes com RCU. As rotinas de higiene oral incluíram a escovagem dos dentes uma ou mais vezes por dia (96,7%) e o uso de pasta com flúor (73,3%). O índice Decayed, Missing and Filled Teeth (média 16,17±6,428) não foi afetado pela frequência de ingestão de refrigerantes, bolos, doces e açucares entre as refeições (P>0,2). Doentes com doença de longa duração apresentaram uma tendência para maior prevalência de cáries dentárias (P=0,06). A maioria possuía taxas de fluxo salivar normais, quer de saliva estimulada (60%) quer de saliva não estimulada (73,3%), assim como taxas de tamponamento salivar elevadas (66,7%). Não foi encontrada associação entre estas características com a idade, género, atividade/duração da doença e tipo de terapêutica farmacológica. Contagens elevadas de Streptococcus mutans e reduzidas de Lactobacillus spp foram observadas em 73,3% e 60% dos doentes, respectivamente. Doentes com doença ativa e maior tempo de evolução apresentaram contagens superiores de Streptococcus mutans. CONCLUSÃO: A prevalência de cárie dentária observada em doentes com RCU foi significativa e não parece ser influenciada pelos hábitos alimentares. A prevalência aumentada de Streptococcus mutans foi o fator de risco maior para a cárie dentária e provavelmente constitui parte da conhecida disbiose oral associada à RCU. Os cuidados dentários a estes doentes deverão ter em consideração esta variação da microbiota.

Microbial species associated with dental caries found in saliva and in situ after use of self-ligating and conventional brackets

Abstract Objectives Enamel demineralization is among the main topics of interest in the orthodontic field. Self-ligating brackets have been regarded as advantageous in this aspect. The aim of this study was to evaluate the break homeostasis in the oral environment and the levels of microorganisms associated with dental caries among the different types of brackets. Material and Methods Twenty patients received two self-ligating brackets: In-Ovation®R, SmartClipTM, and one conventional GeminiTM. Saliva was collected before bonding (S0), 30 (S1) and 60 (S2) days after bonding. One sample of each bracket was removed at 30 and 60 days for the in situ analysis. Checkerboard DNA-DNA Hybridization was employed to evaluate the levels of microbial species as-sociated with dental caries. Data were evaluated by nonparametric Friedman and Wilcoxon tests at 5% significance level. Results The salivary levels of L. casei (p=0.033), S. sobrinus (p=0.011), and S. sanguinis (p=0.004) increased in S1. The in situ analyses showed alteration in S. mutans (p=0.047), whose highest levels were observed to the In-Ovation®R. Conclusions The orthodontic appliances break the salivary homeostasis of microorganisms involved in dental caries. The contamination pattern was different between self-ligating and conventional brackets. The In-Ovation®R presented worse performance considering the levels of cariogenic bacterial species.

Comparison between static and semi-dynamic models for microcosm biofilm formation on dentin

Abstract Microcosm biofilm has been applied to induce carious lesions in dentin. However, no study has been done to compare the impact of the type of model for providing nutrients to microcosm biofilm formation on dentin. Objective This study compared the performance of two kinds of models (static and semi-dynamic) on the biofilm formation and the development of dentin carious lesions. Material and Methods In both models, biofilm was produced using inoculum from pooled human saliva mixed with McBain saliva for the first 8 h (5% CO2 and 37°C). Afterwards, for the static model, the samples were placed in 24-wells microplate containing McBain saliva with 0.2% sucrose, which was replaced at 24 h. In the semi-dynamic model, the samples were submitted to artificial mouth system with continuous flow of McBain saliva with 0.2% sucrose (0.15 ml/min, 37°C) for 10 h a day (for the other 14 h, no flow was applied, similarly to the static model). After 5 days, biofilm viability was measured by fluorescence and dentin demineralization by transverse microradiography. Results Biofilm viability was significantly lower for the static compared with semi-dynamic model, while dentin demineralization was significantly higher for the first one (p<0.05). The static model was able to produce a higher number of typical subsurface lesions compared with the semi-dynamic model (p<0.05). Conclusions The type of model (static and semi-dynamic) applied in the microcosm biofilm may have influence on it's viability and the severity/profile of dentin carious lesions.

Inhibitory effect of reduced graphene oxide-silver nanocomposite on progression of artificial enamel caries

Abstract The use of antimicrobial agents is an efficient method to prevent dental caries. Also, nanometric antibacterial agents with wide antibacterial spectrum and strong antibacterial effects can be applied for prevention of dental caries. Objectives: The aim of this study was to evaluate the inhibitory effect of reduced graphene oxide-silver nanoparticles (rGO/Ag) composite on the progression of artificial enamel caries in a Streptococcus mutans biofilm model. Material and Methods: Enamel specimens from bovine incisors were divided into eight treatment groups (n = 13), as follows: group 1 was inoculated with S. mutans grown in Brain Heart Infusion containing 1% sucrose (1% BHIS), as negative control; groups 2-4 were inoculated with S. mutans grown in the presence of different rGO/Ag concentrations (0.08, 0.12, 0.16 mg/mL) + 1% BHIS; group 5-7 were inoculated with S. mutans grown in the presence of different agents (0.16 mg/mL reduced graphene oxide, 0.16 mg/mL silver nanoparticles, 10 ppm NaF) + 1% BHIS; group 8 was mixed with 1% BHIS, without inoculation. Artificial enamel carious lesions were produced by S. mutans biofilm model for 7 days. Confocal laser scanning microscopy and atomic force microscopy were used to analyze roughness and morphology of the enamel surface. Polarized light microscopy and confocal laser scanning microscopy were employed to measure the lesion depth and the relative optical density (ROD) of the demineralized layer. Results: Compared with the control groups, the rGO/Ag groups showed: (a) reduced enamel surface roughness; (b) much smoother and less eroded surfaces; (c) shallower lesion depth and less mineral loss. Conclusion: As a novel composite material, rGO/Ag can be a promising antibacterial agent for caries prevention.

Efecto Antibacteriano de la Infusión de Orégano ( Origanum vulgare ) sobre el Crecimiento in Vitro de Streptococcus mutans, 2015 / Antibacterial Effect of Oregano Infusion ( Origanum vulgare ) on in Vitro Growth of Streptococcus mutans, 2015

RESUMEN: El Streptococcus mutans es una de las principales bacterias que participa en el desarrollo de la caries dental, una enfermedad de alta prevalencia en la población mundial, y por ende un problema de salud pública. Hoy se intentan buscar alternativas para su prevención, una de ellas es la fitoterapia o uso de plantas medicinales con fines terapéutico beneficiosos para la salud. Evaluar efecto antibacteriano del Origanum vulgare a diferentes concentraciones sobre el crecimiento in vitro de Streptococcus mutans. Se utilizaron cepas bacterianas de Streptococcus mutans previamente aisladas, se realizó una siembra bacteriana en 24 placas Petri con agar mitis salivarius. Se prepararon infusiones de orégano a 8 concentraciones diferentes (1 %, 5 % y 10 %, 20 %, 40 %, 60 %, 80 % y 100 %) y se aplicaron en perforaciones realizadas previamente en las placas de agar (4 perforaciones por placa para las infusiones de orégano y 2 para las placas de controles). Se llevó a incubadora por 48 horas y posteriormente se realizó la medición de los halos de inhibición. Los resultados fueron negativos para las infusiones de orégano al 1 %, 5 % y 10 %, debido a que no presentaron halos de inhibición bacteriana; mientras que para las infusiones al 20 %, 40 %, 60 %, 80 % y 100 % los resultados fueron positivos. El orégano posee efecto antibacteriano sobre el crecimiento de Streptococcus mutans en infusiones sobre el 20 % de concentración, siendo la solución madre preparada a partir de 20 gramos de hojas secas de orégano (Origanum vulgare) y 200 ml de agua destilada hervida. Este efecto es antibacteriano es directamente proporcional a la concentración de la infusión. El orégano podría ser utilizado como una alternativa de colutorio, pasta dental u otros coadyuvantes de higiene bucal para prevenir la aparición de caries.

ABSTRACT: Streptococcus mutans is one of the main bacteria in the development of dental caries, a disease with high prevalence in the world population, and therefore a public health problem. There is current research to find prevention alternatives one of these is the use of medicinal plants for therapeutic purposes beneficial to health. To evaluate the antibacterial effect of Origanum vulgare at different concentrations on in vitro growth of Streptococcus mutans, previously isolated bacterial strains of Streptococcus mutans were used. Bacterial seeding was carried out in 24 petri dishes with agar Mitis salivarius. Oregano infusions were prepared at 8 different concentrations (1 %, 5 % and 10 %, 20 %, 40 %, 60 %, 80 % and 100 %) and applied in predrilled holes in the agar plates (4 perforations per plate for the oregano infusions and 2 for control plates). They were maintained in an incubator for 48 hours and measurement of the inhibition zones was subsequently carried out. The results were negative for infusions of oregano at 1 %, 5 % and 10 %, as they did not present halos of bacterial inhibition; while results were positive for infusions at 20 %, 40 %, 60 %, 80 % and 100 %. Results show that oregano has an antibacterial effect on the growth of Streptococcus mutans in infusion concentrations above 20 %, with the basic solution prepared from 20 g of dried oregano leaves (Origanum vulgare) and 200 ml of boiled distilled water. This antibacterial effect is directly proportional to the concentration of the infusion. Oregano could be used as an alternative mouthwash, toothpaste or other oral hygiene adjuvants to prevent the incidence of caries.

Susceptibility of cariogenic microorganisms to phytoconstituents / Susceptibilidade de microrganismos cariogênicos a fitoconstituintes

Abstract This study aimed to evaluate the in vitro antibacterial activity of the phytochemicals thymol, linalool, and citronellol against Streptococcus mutans, Streptococcus salivarius and Streptococcus oralis. Disk diffusion screening on solid medium and measurement of the diameter of the bacterial growth inhibition halos was the technique utilized. The Minimum Inhibitory Concentration (MIC) of the substances was determined using serial substance dilutions and microdilution technique in Brain Heart Infusion culture medium. After incubation for 24 hours in an oven at 37 °C, plate reading was completed and confirmed by visual method using 2,3,5 triphenyl tetrazolium chloride dye. The Minimum Bactericidal Concentration (MBC) was determined from MIC subcultures. Assays were performed in triplicate, and chlorhexidine was used as a positive control. The diameters in mm of the growth inhibition halos ranged between 7.3 and 10.7 for S. mutans, 7.3 and 10.0 for S. oralis, and 8.2 and 9.8 for S. salivarius. The MIC and MBC values obtained converged, ranging from maximum values in the presence of Linalool (1,250.0 mg/mL, 2,500.0 mg/mL and 2,500.0 mg/mL, respectively, for S. mutans, S. oralis, and S. salivarius); and minimum values with Thymol (312.5 μg/ml, 156.2 μg/mL and 156.2 μg/ml, respectively for S. mutans, S. oralis, and S. salivarius). All the tested phytochemicals displayed antibacterial activity, thus representing substances with potential applications in preventing tooth decay.

Resumo Este estudo objetivou avaliar a atividade antibacteriana in vitro dos fitoquímicos timol, linalol e citronelol sobre Streptococcus mutans, Streptococcus salivaris e Streptococcus oralis. Utilizou-se a técnica de discos de difusão em meio sólido e medição do diâmetro dos halos de inibição. A concentração inibitória mínima (CIM) das substâncias foi determinada utilizando diluições em série das substâncias e técnica de microdiluição em meio de cultura de Brain Heart Infusion. Após incubação durante 24 horas em estufa a 37 °C, a leitura da placa foi confirmada pelo método visual usando o corante 2,3,5 trifenil cloreto de tetrazólio. A concentração bactericida mínima (CBM) foi determinada a partir de subculturas de MIC. Os ensaios foram realizados em triplicata, e clorexidina foi usada como um controle positivo. Os diâmetros dos halos de inibição do crescimento variaram entre 7,3 e 10,7 por S. mutans, 7,3 e 10,0 por S. oralis, e 8,2 e 9,8 para S. salivaris. Os valores de CIM e CBM obtidos variaram de valores máximos na presença de linalol (1.250,0 mg/mL, 2.500.0 mg/mL e 2.500.0 mg/mL, respectivamente, para o S. mutans, S oralis e S. salivaris); a valores mínimos com timol (312,5 μg/ml, 156,2 μg/mL e 156,2 μg/ml, respectivamente para S. mutans, S. oralis e S. salivaris). Todos os fitoquímicos testados apresentaram atividade antibacteriana, representando, assim, substâncias com potencial de aplicações na prevenção da cárie dentária.

Atividade antimicrobiana de Stevia rebaudiana Bertoni e de adoçantes não calóricos sobre bactérias cariogênicas: estudo in vitro / Antimicrobial activity of Stevia rebaudiana Bertoni and non-caloric sweeteners on cariogenic bacteria: in vitro study

Objetivo: avaliar a atividade antimicrobiana in vitro da planta Stevia rebaudiana Bertoni e de adoçantes não calóricos sobre o crescimento de Streptococcus mutanse Lactobacillus casei, micro-organismos cariogênicos presentes na cavidade bucal. Materiais e método: o estudo foi realizado utilizando as cepas padrões de S.mutans (UA159) e L. casei (ATCC7469). Foram avaliados diferentes compostos não calóricos substitutos dasacarose nas concentrações de 1%, 5% e 10%: eritritol(ER), Fit Sucralose® (SU), Stevita® (ST), solução de Steviarebaudiana Bertoni (SSr) e, como controle positivo,digluconato de clorexidina (DC). A análise do efeito inibitório desses compostos no crescimento das bactériasfoi feita por meio da técnica de difusão em ágar. Resultado:observou-se que existe um efeito inibitório decrescimento de ambos os micro-organismos por parte da SSr e do ER, enquanto os demais adoçantes testa dosnão tiveram efeito inibitório sobre esses micro-organismos.Conclusão: os resultados demonstram que SSR eER apresentam efeito inibidor no crescimento das cepastestadas de S. mutans e L. casei. (AU)

Objective: The study evaluated the in vitro antimicrobial activity of the Stevia rebaudiana Bertoni plant and non-caloric sweeteners on the growth of Streptococcus mutans and Lactobacillus casei, which are cariogenic microorganisms present in the oral cavity. Materials and method: The study was conducted using the standard strains of S. mutans (UA159) and L. casei (ATCC7469). Different non-caloric compounds were evaluated at concentrations of 1%, 5%, and 10%: erythritol (ER), Fit Sucralose™ (SU), Stevita™ (ST), Stevia rebaudiana Bertoni solution (SSr), and chlorhexidine digluconate (CD) as positive control. The inhibitory effect of these compounds on the growth of bacteria were analyzed by the agar diffusion technique. Result: There was a growth inhibition effect for both microorganisms by SSr and ER, whereas the other sweeteners tested had no inhibitory effect on the microorganisms. Conclusion: The results showed that SSr and ER present an inhibitory effect on the growth the strains tested of S. mutans and L. casei. (AU)

Validación de un Cuestionario para Evaluar Riesgo de Caries en Preescolares en Santiago, Chile / Validation of a Questionnaire to Assess Risk of Caries in Preschool-Age Children in Santiago, Chile

RESUMEN: La Caries Temprana de la Infancia (CTI) es una forma de caries dental agresiva que afecta a niños, y en el último reporte nacional reveló una prevalencia de caries del 50 % en niños de 4 años de edad de la Región Metropolitana de Santiago (Soto et al., 2007). El objetivo de este estudio es validar un cuestionario que permita recolectar información relacionada con diversos factores de riesgo de caries en niños preescolares. Para la validación del cuestionario se determinó la validez de convergencia y discriminación, la consistencia interna y la confiabilidad test retest del instrumento en dos muestras independientes. Se aplicó el instrumento al cuidador principal de 118 preescolares entre 24 a 71 meses de edad, que asisten a jardines infantiles de dependencia particular (bajo riesgo de caries) y la Fundación INTEGRA (alto riesgo de caries) en la Región Metropolitana de Santiago, Chile. Se realizaron exámenes clínicos dentales por 2 odontólogos calibrados utilizando en el criterio OMS e ICDAS II. Se estimó un modelo de regresión logística y se evalúo la capacidad de discriminación del puntaje a través de una curva ROC. El cuestionario mostró una validez de discriminación de 0,95 entre ambos grupos y de la pregunta global 0,61 y una consistencia interna del cuestionario de 0,72. En la validez de convergencia se encontró que no existe asociación estadísticamente significativa entre el puntaje del cuestionario y la pregunta global dicotomizada (OD) 1,061. No obstante, se evidenció que si existe asociación estadísticamente significativa entre el puntaje del cuestionario y el grupo riesgo de caries (bajo y alto) (OD) 1,961. La estabilidad temporal mediante comparaciones Test - Retest calculado con el índice de Kappa osciló entre 0,37 a 1. Por lo tanto, se puede concluir que el presente cuestionario es un instrumento válido para discriminar riesgo de caries, permitiendo un mejor análisis de los determinantes de la caries dental en la población preescolar chilena.

ABSTRACT: Early Childhood Caries (ECC) is an aggressive form of tooth decay, and the last national unpublished reports reveal a caries prevalence of 50 % at 4 years of age in children, in the Santiago Metropolitan Region (Soto et al., 2007). The objective of this study is to validate a questionnaire that allows the collection of information related to several caries risk factors in preschoolchildren. For the validation of the questionnaire, the convergence and discrimination validity, the internal consistency and the retest, test reliability of the instrument were determined in two independent samples. The instrument was applied to the main caregiver of 118 preschoolers between 24 and 71 months of age, who attend private childcare centers (low caries risk) and the INTEGRA Foundation childcare (high caries risk) in the Metropolitan Region of Santiago, Chile. Dental clinical examinations were performed by two calibrated dentists using the OMS and ICDAS II criteria. A logistic regression model was estimated and the ability to discriminate the score through an ROC curve was evaluated. The questionnaire showed a validity of discrimination of 0.95 between both groups and of the global question 0.61 and an internal consistency of the questionnaire of 0.72. In the convergence validity, it was found that there is no statistically significant association between the questionnaire score and the dichotomized global question (RE) 1.061. However, it was evidenced that there is a statistically significant association between the questionnaire score and the caries risk group (low and high) (OD) 1.961. Temporal stability by means of Test - Retest comparisons calculated with the Kappa index ranged from 0.37 to 1. Therefore, it can be concluded that the present questionnaire is a valid instrument for discriminating caries risk, allowing a better analysis of the determinants of dental caries in the Chilean preschool population.

Presence and count of S. mutans in children with dental caries: before, during and after a process of oral health education

Dental caries is an infectious, multifactorial, localized, transmissible process that leads to the destruction of hard dental tissue. Streptococcus mutans is considered to be the main microorganism associated with its development. The aim of this study was to determine presence and count of S. mutans in saliva samples from children with dental caries before and after an educational process including interviews, lessons, lectures, educational workshops and recreational activities on the importance of oral care and hygiene. Twentythree 3 to 6 year old schoolchildren provided 3 unstimulated saliva samples: one before the educational process, one at 3 months and one at 6 months into the educational process. The samples were serially diluted and plated on Mitis Salivarius agar supplemented with bacitracin and 20% sucrose, and incubated anaerobically for 2 days at 37oC. Presumptive S. mutans isolates were identified with biochemical tests. Before the beginning of the educational process, and at 3 and 6 months into the educational process, S. mutans was found, respectively, in 22 (95.6%), 15 (65.2%) and 10 (43.5%) of the 23 children. The S. mutans count was reduced by 64.8% and 86.6% at 3 and 6 months, respectively, compared to the levels found before the educational process. These results indicate that educational intervention produced a significant reduction in S. mutans levels in the saliva of children with dental caries at 3 and 6 months into the educational process (AU)

La caries dental es un proceso infeccioso multifactorial, localizado y transmisible que se caracteriza por la destrucción del tejido dental duro. Streptococcus mutans es considerado el principal microorganismo asociado al desarrollo de esta enfermedad. El objetivo de este estudio fue determinar la presencia y recuento de S. mutans en saliva de niños con caries dental antes y después de un proceso educativo. Con este fin se tomó saliva no estimulada de 23 niños con caries dental pertenecientes a un centro educativo con edades de 3 a 6 años. En todos los niños se tomaron 3 muestras de saliva: antes del proceso educativo y a los 3 y 6 meses de iniciado el proceso educativo. El proceso educativo consistió en entrevistas, enseñanzas, conferencias, talleres educativos y actividades lúdicas sobre la importancia del cuidado e higiene oral. Después de su recolección, las muestras de saliva fueron serialmente diluidas y sembradas en Agar Mitis Salivarius con bacitracina y sacarosa al 20%. Los medios de cultivo sembrados se incubaron en anaerobiosis durante 2 días a 37ºC y los aislamientos presuntivos de S. mutans se identificaron con pruebas bioquímicas. Antes del inicio del proceso educativo, a los 3 y 6 meses de iniciado el proceso educativo se encontró S. mutans, respectivamente, en 22 de los 23 niños (95.6%), en 15 de los 23 niños (65.2%) y en 10 de los 23 niños (43.5%). En cuanto al recuento de S. mutans, se encontró una reducción de 64.8 % y 86.6% a los 3 y 6 meses, respectivamente, en comparación a los niveles encontrados antes del inicio del proceso educativo. En conclusión, los resultados indican que la intervención educativa realizada produjo una reducción significativa en los niveles de S. mutans en saliva de niños con caries dental después de 3 y 6 meses de iniciado el proceso educativo (AU)

The role of human milk and sucrose on cariogenicity of microcosm biofilms

Abstract This study investigated the effect of human milk, alone and associated with sucrose, in the cariogenicity of biofilms in a microcosm biofilm model and compared with the cariogenicity of sucrose and bovine milk. Microcosm biofilms were grown in enamel discs in 24-well plates. Six growth conditions were studied: DMM (chemically defined artificial saliva - negative control), DMM with 1% of sucrose (DMM+s) (positive control), human milk with DMM, human milk with DMM+s, bovine milk with DMM, and bovine milk with DMM+s. After 5 days, the outcome variables surface hardness change (%SHC), microbiological composition of biofilms, and pH of supernatant were analyzed. All groups had significantly lower hardness loss compared to the DMM group with 1% of sucrose. Human and bovine milk associated with sucrose showed higher hardness loss. The supernatant pH values after 6 hours of different treatments were similar for the groups sucrose and human milk associated with sucrose (p>0.05). After 18 hours at rest in pure DMM, an increase in the pH of the supernatant was observed. Higher values of total microorganisms count were found for sucrose and bovine milk groups compared to the group supplemented only by DMM. Bovine milk group showed greater amount of total aciduric microorganisms in comparison to human milk group. Within the limits of this study, it can be infered that both human and cow milks have some cariogenic potential, although differing from sucrose in terms of mineral loss.

Dental caries and bacterial load in saliva and dental biofilm of type 1 diabetics on continuous subcutaneous insulin infusion

Abstract Objectives Since most of the studies evaluates diabetics on multiple daily injections therapy and continuous subcutaneous insulin infusion may help gain better metabolic control and prevent complications, the objective of this study was to evaluate the prevalence of dental caries, the unstimulated salivary flow rate and the total bacteria load, Streptococcus spp. levels and Lactobacillus spp. levels in saliva and supragingival dental biofilm of type 1 diabetics on insulin pump. Material and Methods Sixty patients with type 1 diabetes on insulin pump and 60 nondiabetic individuals were included. The dental caries evaluation was performed using ICDAS and the oral hygiene was assessed according to Greene and Vermillion Simplified Oral Hygiene Index. Unstimulated saliva and supragingival dental biofilm were collected. Total bacteria, Streptococcus spp. and Lactobacillus spp. was quantified by qPCR. Results Patients with type 1 diabetes had a higher prevalence of dental caries and filled and missing teeth when compared with the control group. These patients were associated with more risk factors for the development of dental caries, namely a lower unstimulated salivary flow rate and a higher bacterial load in saliva and dental biofilm. Conclusion Some risk factors related to dental caries were associated with type 1 diabetics. An early diagnosis combined with the evaluation of the risk profile of the diabetic patient is imperative, allowing the dental caries to be analyzed through a perspective of prevention and the patient to be integrated into an individualized oral health program.

Effects of a food enriched with probiotics on Streptococcus mutans and Lactobacillus spp. salivary counts in preschool children: a cluster randomized trial

Abstract Probiotics have provided benefits to general health, but they are still insufficient to dental health. Objective: This study aimed to evaluate milk supplemented with probiotic bacteria and standard milk, measured by levels of Streptococcus mutans (S. mutans) and Lactobacillus spp., in 3-4-year-old children after 9 months of intervention. Material and Methods: The study was a triple-blind, placebo-controlled, randomized trial. The sample was composed of 363 preschoolers attending five child development centers in Cali, Colombia. They were randomized to two groups: children in the intervention group drank 200 mL of milk with Lactobacillus rhamnosus 5x106 and Bifidobacteruim longum 3x106, and children in the control group drank 200 mL of standard milk. Interventions occurred on weekdays and information was gathered through scheduled clinical examination. The primary result was the number of colony forming units (CFU) of S. mutans and Lactobacillus spp. in the saliva. Secondary results were dental caries, rated by the International Caries Detection and Assessment System (ICDAS), dental plaque, pH, and salivary buffer capacity. Results: The proportion of S. mutans was lower in the intervention group compared with the control group after 9 months; however, the differences did not reach statistical significance (p=0.173); on the other hand, statistically significant differences between groups were found in the CFU/mL of Lactobacillus spp. (p=0.002). There was not statistically significant difference in the prevalence of dental caries for both groups (p=0.767). Differences between groups were found in the salivary buffering capacity (p=0.000); neither salivary pH nor dental plaque were significantly different. Conclusions: Regular consumption of milk containing probiotics bacteria reduced CFU/mL of Lactobacillus spp. and increased salivary buffering capacity at 9 months of consumption.