RESUMEN
OBJECTIVES: The aim of this study was to analyze the related factors to dental caries incidence and increments of DMFT index in children's permanent teeth. METHODS: The subjects were 249 elementary school children at the baseline survey. At the four-year follow-up survey, number of subjects reduced to 141. In the first year, all subjects submitted the responses of questionnaire composed of demographic variables and oral health behaviors. They also received oral examination and tests of salivary excretion rate, salivary buffer capacity, Dentocult(R) SM and Dentocult(R) LB. In the first to fourth follow-up year, they received oral examinations. The relation of oral health-related factors with caries incidence and increments of DMFT and DMFS index was analyzed by chi-square test, ANOVA, logistic regression analysis and generalized linear model analysis using Poisson distribution. RESULTS: At four-year follow-up survey, subjects whose Dentocult(R) SM was 2 or higher compared to subjects whose Dentocult(R) SM was 1 or less and subjects whose Dentocult(R) LB was 2 or higher compared to subjects whose Dentocult(R) LB was 1 or less had higher DMFT index increments. In DMFT index increments, the adjusted odds ratio of subjects whose dfs index of primary molars was 11 and more was 4.30 compared to subjects whose dfs index of primary molars was 0 adjusted for gender, daily frequency of toothbrushing and eating between meal, mother's job, oral health education, salivary excretion, salivary buffer capacity and Dentocult(R) SM test. CONCLUSIONS: It was suggested that the caries incidence and increments of DMFT index in permanent teeth should be highly associated with salivary lactobacillus count and dfs index of primary molars.