Risk factors of dental caries among preschool children in Japan

Objectives: To evaluate the risk factors for the pre-school children in Japan Methods: Nine elementary schools from 13 at two areas in Japan were selected. Totally, 656 children were participated in this study. Oral cariogenic bacteria were evaluated by improved MSB and Logosa SL at pre-school medical check-up. Other factors such as usage of fluoride containing dentifrices, experience of fluoride varnish at private dental office, taking regular check-ups, use of mouthwash with fluoride, daily times of intakes of sweet juice and sweet snacks were evaluated by questioners. The oral examinations were carried out at annual check-ups and the follow up periods were three years. Results: By the multivariate logistic regression analysis revealed that only tree factors: gender, salivary levels of the mutans streptococci and with or without dental caries in primary dentition had statistically significant co-relation with the incidence of the dental caries. The odds ratios were 2.26 for female, 1.25 for the mutans streptococci (log CFU) and 1.82 for dental caries in primary dentition. Conclusion: The prevalence of the dental caries has been declined in Japan, however, the mutans streptococci have been remained to be risk factors for the dental caries.