Analysis Of Factors Associated With Susceptibility And Metagenomics Study Of Cariogenic Bacteria In Plaque Biofilm Of Early Childhood Caries In Qingdao

Object: To analyze factors associated with susceptibility of Early childhood caries(ECC),screen populations with high-risk for ECC, and provide targeted guidance for ECC prevention. Analysis of bacterial species information associated with ECC provided new targets for etiology study and laid a solid foundation for ECC risk assessment and choosing treatment strategies.Methods: 196 children at 3-6 years of age in Qingdao were selected for oral examination.Parents or guardians of the participants completed the questionnaires and decayed-missing-filled tooth(dmft) scores were recorded. Differences in caries condition and oral health behavior in different families were compared. Risk factors related to ECC were screened. While 90 children were randomly collected dental plaque. Bacterial genomic DNA of plaque biofilm was optimized purification, separation, PCR amplification and Miseq high-throughput sequencing. To analyze the difference of microbes’ genetic makeup in plaque biofilm, and bacterial species information associated with ECC.Results: 196 children completed questionnaires and clinical examination, and 90 children completed dental plaque collection. There were significant differences among free of caries, low caries and high caries group in three parameters: frequencies of sweets consumption daily and before sleeping and after brushing, and whether parents helped to brush(P<0.01). Combined factors such as parents’ education level, oral health knowledge,attitudes, family income, age of children beginning to brush, and frequency of brushing were also significantly correlated with ECC(P<0.05). No significant differences were observed among the three groups in the factors including duration of brushing, frequency of mouth rinsing after meals daily, brushing with fluoride toothpaste, using pacifier during sleep, birth condition, feeding situation, nursing state, and physical condition of the mother during pregnancy(P>0.05). Among the three groups of children gathered dental plaque, Streptococcus and Porphyromonas were no significantly different(P>0.05).But Prevotella and Neisseria were significantly different between free of caries and low caries group(P<0.05); Neisseria, Lactobacillus and Lautropia were significantly different between free of caries and high caries group(P<0.05); Actinomyces and Lactobacillus were significantly different between low caries and high caries group(P<0.05);Streptococcus mutans NLML8 were significantly different between low caries and high caries group, free of caries and high caries group(P<0.01).Conclusions: High frequencies of sweets consumption, incorrect brushing method,starting brushing at later stage, and low brushing frequency are susceptible factors for ECC. Children’s oral plaque biofilm was formed by the complex microbial community structure. Streptococcus mutans NLML8, Lactobacillus, Actinomyces, Prevotella and Neisseria can increase the risk of ECC, however Lautropia can reduce the risk of ECC.Emphasizing oral health knowledge to parents and guardians, control the manner and frequency of sweets consumption and bacterial infections are very important to prevent ECC.