High-throughput sequencing identifies salivary microbiota in Chinese caries-free preschool children with primary dentition / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

OBJECTIVES@#The study aimed at identifying salivary microbiota in caries-free Chinese preschool children using high-throughput sequencing.@*METHODS@#Saliva samples were obtained from 35 caries-free preschool children (18 boys and 17 girls) with primary dentition, and 16S ribosomal DNA (rDNA) V3-V4 hypervariable regions of the microorganisms were analyzed using Illumina MiSeq.@*RESULTS@#At 97% similarity level, all of these reads were clustered into 334 operational taxonomic units (OTUs). Among these, five phyla (Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, and Candidate division TM7) and 13 genera (@*CONCLUSIONS@#Our results revealed the diversity and composition of salivary microbiota in caries-free preschool children, with little difference between male and female subjects. Identity of the core microbiome, coupled with prediction of gene function, deepens our understanding of oral microbiota in caries-free populations and provides basic information for associating salivary microecology and oral health.

Caries-related factors and bacterial composition of supragingival plaques in caries free and caries active Algerian adults

Objective: To compare oral hygiene practices, education and social background, food intake and oral malodor of Algerian adults suffering from dental caries with normal controls, and to determine and compare the bacterial composition of the supragingival plaques from the above-mentioned groups. Methods: Participants completed a questionnaire and were clinically examined for dental caries using decayed, missing and filled teeth index according to the criteria laid down by the World Health Organization. Supragingival plaque samples were collected from 50 caries-free adults (CF) and 50 caries-active adults (CA). Standard procedures of culture and identification of aerobic and anaerobic bacteria were used. Data were analyzed using Chi-square test. Results: A total of 117 bacterial strains were isolated from supragingival plaques in CF group subjects, 76 (64.96%) of them belonged to 9 aerobic genera, and 41 (35.04%) to 9 anaerobic genera (P<0.05). While in the second group, 199 strains were isolated, 119 (59.80%) of the strains belonged to 10 aerobic genera and 80 (40.20%) to 10 anaerobic bacteria (P<0.05). Streptococcus mutans, Enterococcus faecium, Aerococcus viridans, Actinomyces meyeri, Lactobacillus acidophilus and Eubacterium limosum showed a significantly higher prevalence in the CA group (P<0.05). The findings revealed that CA group had a high sugar intake (80%). A significantly higher frequency of tooth brushing (P<0.000) and a significantly less self-reported oral malodor (P<0.000) and tooth pain (P<0.000) were found in CF group, while there was no association of socioeconomic levels and intake of meal snacks with dental caries. Conclusions: This study confirms the association of some aciduric bacteria with caries formation, and a direct association of sugar intake and cultural level with dental caries. Furthermore, oral hygiene practices minimize the prevalence of tooth decay.

Caries-related factors and bacterial composition of supragingival plaques in caries free and caries active Algerian adults

Objective To compare oral hygiene practices, education and social background, food intake and oral malodor of Algerian adults suffering from dental caries with normal controls, and to determine and compare the bacterial composition of the supragingival plaques from the above-mentioned groups. Methods Participants completed a questionnaire and were clinically examined for dental caries using decayed, missing and filled teeth index according to the criteria laid down by the World Health Organization. Supragingival plaque samples were collected from 50 caries-free adults (CF) and 50 caries-active adults (CA). Standard procedures of culture and identification of aerobic and anaerobic bacteria were used. Data were analyzed using Chi-square test. Results A total of 117 bacterial strains were isolated from supragingival plaques in CF group subjects, 76 (64.96%) of them belonged to 9 aerobic genera, and 41 (35.04%) to 9 anaerobic genera (P < 0.05). While in the second group, 199 strains were isolated, 119 (59.80%) of the strains belonged to 10 aerobic genera and 80 (40.20%) to 10 anaerobic bacteria (P < 0.05). Streptococcus mutans, Enterococcus faecium, Aerococcus viridans, Actinomyces meyeri, Lactobacillus acidophilus and Eubacterium limosum showed a significantly higher prevalence in the CA group (P < 0.05). The findings revealed that CA group had a high sugar intake (80%). A significantly higher frequency of tooth brushing (P < 0.000) and a significantly less self-reported oral malodor (P < 0.000) and tooth pain (P < 0.000) were found in CF group, while there was no association of socioeconomic levels and intake of meal snacks with dental caries. Conclusions This study confirms the association of some aciduric bacteria with caries formation, and a direct association of sugar intake and cultural level with dental caries. Furthermore, oral hygiene practices minimize the prevalence of tooth decay.

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

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

Dental caries in preschoolers from communes with fluoridated and non-fluoridated public water supplies in Chile / Cárie dentária em pré-escolares de comunidades com e sem fluoretação de água no Chile

Purpose: To determine the prevalence and severity of dental caries in three- to five-year-old preschool children from two communes in Chile: one with a fluoridated public water supply and the other with a non-fluoridated public water supply. Methods: Study design: Cross-sectional observational study. The sample was composed of 200 children from three to five years old, with good general health, of low socioeconomic status, attending four kindergarten schools of the Metropolitan Region of Santiago, Chile. Two schools were located in the commune of Maipú, which does not have fluoridated public water, and two schools were located in the commune of Peñalolen, which has had fluoridated public water since 1996, at a fluoride concentration of 0.6 mg/L. The WHO (World Health Organization) methodology was used to measure the percentage of caries-free children, and the dmft index was used to measure the severity of the disease. Results: The results showed that 24% of the children in Maipú were caries free, compared to 55% in Peñalolen. The dmft index was 3.38 and 1.84 in Maipú and Peñalolen, respectively. These indices increased with age. Conclusion: The prevalence and severity of dental caries in three- to five-year-old preschoolers were higher in Maipú, the commune with non-fluoridated water, than in Peñalolen, the commune with fluoridated water.

Objetivo: Determinar a prevalência e severidade da doença cárie dentária em crianças pré-escolares de 3 a 5 anos de idade em creches no Chile, localizadas em uma comunidade sem fluoretação da água de abastecimento público e em outra comunidade com agua fluoretada. Metodologia: Delineamento do estudo: observacional, transversal. A amostra foi composta por 200 crianças de 3 a 5 anos, com boa saúde geral, pertencentes a baixos estratos sociais, de quatro creches da Região Metropolitana de Santiago, dois do município de Maipú sem fluoretação da água de abastecimento público e duas do município de Peñalolén com fluoretação desde 1996, com concentração de flúor de 0,6 mg/L. A metodologia da OMS foi utilizada para o registro da percentagem de crianças livres de cárie e o índice cpod foi usado para medir a severidade da doença. Resultados: A porcentagem de crianças livres de cárie foi de 24% em Maipú e 55% em Peñalolén, com índice cpod de 3,38 e 1,84, respectivamente. Estes resultados aumentaram com a idade. Conclusão: A prevalência e severidade da cárie dentária em pré-escolares de 3 a 5 anos em Maipú (agua não fluoretada) foram superiores aos observados em Peñalolén (água fluoretada).

Prevalence of dental caries in preschool children in Peñaflor, Santiago, Chile / Prevalência de cárie dentária em crianças residentes em Peñaflor, Santiago, Chile

Purpose: Despite the reduction in the prevalence of dental caries in Chile, very little is known about the prevalence of this disease in deciduous teeth. The aim of the present study was to evaluate the prevalence of dental caries in children aged 3 to 5 year-old of Peñaflor, a semirural commune in Santiago, Chile. Methods: A total of 94 children from families of low socioeconomic status were examined. One trained and calibrated dentist (kappa 0.87) performed the clinical examinations and recorded data on caries free children, caries severity, and dmft index, using the WHO protocols. Results: The results showed that 50% of the 3 year-old children were caries-free compared to 42.2% at the age of 5 year-old. There was no statistically significant gender difference in the prevalence of the disease. For the total sample, the percentage of caries-free children was 43.2%. The dmft index in the study population at 3, 4, and 5 year-old was 1.30, 2.51, and 2.52, respectively. Conclusion: This study showed that children in Peñaflor commune have not reached the WHO goals proposed for the year 2000, which indicates that this population requires the adoption of additional preventive and restorative strategies to improve oral health.

Objetivo: Apesar da redução de prevalência de cárie no Chile, muito pouco se sabe sobre a prevalência da doença em dentes decíduos. O objetivo deste estudo foi avaliar a prevalência de cárie em crianças de 3 a 5 anos de idade em Peñaflor, uma comunidade semirrural em Santiago, Chile. Metodologia: A amostra foi constituída por um total de 94 crianças de famílias de baixo nível sócio-econômico. Um cirurgião dentista previamente treinado e calibrado (kappa 0.87) realizou os exames clínicos e registrou a porcentagem de crianças sem cáries, severidade da cárie e índice ceo-s, usando a metodologia descrita pela OMS.Resultados: Os resultados mostraram que 50% das crianças de 3 anos não apresentavam cáries em comparação com 42,2% das crianças de 5 anos de idade. Não houve diferença estatisticamente significativa entre gênero para a prevalência da doença. Para o total da amostra, a porcentagem de crianças sem cáries foi de 43,2%. O índice ceo-s na população estudada foi 1,30; 2,51 e 2,52, aos 3, 4 e 5 anos de idade, respectivamente. Conclusão: Este estudo mostrou que as crianças da comunidade de Peñaflor não alcançaram os objetivos propostos pela OMS para o ano 2000. Isto indica que esta população necessita da aplicação de estratégias preventivas e restauradoras adicionais.

Salivary proteins in children aged from 3 to 4 years / 实用口腔医学杂志

Objective: To explore levels of salivary IgA, lysozyme, lactate dehydrogenase, alkaline phosphatase and total proteins in unstimulated (UWS) and stimulated (SWS) whole saliva of caries-free children. Methods: 94 caries-free children, aged from 42 to 54 months, were recruited from urban kindergartens in Beijing. 2 ml UWS and 2 ml SWS were collected from each child to measure salivary IgA, lysozyme, lactate dehydrogenase, alkaline phosphatase and total proteins. Results:1) There were no differences in salivary proteins between boys and girls in both UWS and SWS, except total proteins. In UWS, the concentration of total proteins in girls was lower than that in boys (P0.05). 2) The concentration of IgA in SWS was significantly lower than that in UWS (P0.05). Conclusion:In 3-to 4-year old children, the protein composition in stimulated whole saliva is different from that in unstimulated whole saliva, and it is also different between genders. Therefore, it is more reliable to measure salivary proteins in both UWS and SWS when studying saliva of children.