Colonização de diferentes sítios bucais por Streptococcus mutans e Lactobacillus sp. e associações com variáveis determinantes em crianças de 1 a 5 anos de idade

Abstract

The incidence of early childhood caries is a public health problem which may have an impact on the permanent dentition. Factors associated with caries are cariogenic microbial component, contact time of the microbiological component to the tooth, frequency of contact, decreased salivary secretion and pH, diet and oral care and intrinsic factors of the host. In childhood, there are the acquisitions of Streptococcus mutans and Lactobacillus sp. that combined with a cariogenic diet and lack/scarcity of oral hygiene, resulting in the appearance of caries. Microbiological studies attempt to relate the increase in the microbial colonization of the cariogenic phenomenon, but the analysis methods are nonstandardized and the results are not consensual. This study aimed to determine the levels of oral colonization of Streptococcus mutans and Lactobacillus sp. in different oral sites and associated predisposing conditions for children of 1 to 5 years of age. This was an observational, experimental, descriptive and transversal study performed in children and their mothers or guardians registered at the Family Health Strategy I Lourdes Montes Claros MG. Included were children who did not use antimicrobials and their mothers or guardians agree to be parto f the study and signed na informed consent. Patients were evaluated by clinical examination and submitted to the collection of saliva (buccal mucosa and floor of the mouth) and biofilm and their parents answered a structured questionnaire about hygiene, diet and socioeconomic dimensions. The saliva samples were plated on selective media for quantification and presumptive identification for Streptococcus mutans and Lactobacillus sp. The study included 84 patients and the age-stratum of 25 to 30 months (21.4%) was the most common. The DMFT found was considered low (0.98) and associated with males and not associated with microbial counts in the biofilm. Of these children, 75.9% receive some oral care hygiene. More than 70% of parents reported having received some guidance about caring for the oral health of children. The bacterial counts of Streptococcus mutans and Lactobacillus sp. were statistically different at all sites evaluated and was higher in the oral mucosa (p <0.05). There was homogeneity of presence or absence for Streptococcus mutans to all sites and heterogeneity of Lactobaccilus sp. There was relation of some counts associated with increased risk for caries with gender, socioeconomic status, maternal education, and intake of milk over 12 months, but not a universal finding for all habitats. We observed that the mucosa is the niche with highest score for both microorganisms; perceived differences between homogeneity and heterogeneity of presence for both and the association of variables such as gender, age, socio-economic, cultural, and type of feeding with higher risk for caries in some niches. It is recommended to this study the performance of standard collections in specific niches in the oral cavity to measure the count of these microorganisms.