Abstract
We made an analysis of 9-year secular caries prevalence of a set children of a region lacking in a dental treatment system. Also with the view of examining the effectiveness of the caries activity test (Cariostat) as a predictable index of the caries prevalence, we examined the relationship of the caries activity of same group with its subsequent caries prevalence. The following conclusions were obtained;
1) For caries prevalence, both primary and permanent teeth showed higher values than the prefectural mean value. Secular change of the number of caries teeth was most frequent for children age ca.6 and showed a decreasing (up to age ca.11) and subsequently a reincreasing tendency.
2) The results of the judgment by the Cariostat indicated the most highly cariesactive age-group to be 6∼7 year old children, best expressing the caries prevalence at the actual point of Cariostat, with CSI as an index.
3) The results of the judgment of primary dentition period by Cariostat and CSI, df+DMF teeth number showed a positive correlation from the beginning of the mixed dentition to the following fourth year, which correlation disappeared thereafter and came to reappear at the completement of the permanent dentition. The above results and DMF teeth number showed a correlation up to 3∼4 years following the beginning of eruption of permanent teeth and 1∼2years before the accomplishment of permanent dentition.
4) The results of the judgment of mixed dentition period by Cariostat showed a correlation with the caries prevalence at the permanent dentition period, and especially the most significant positive correlation with the results of the judgment at the beginning of permanent teeth.
The above indicated that the results of the judgment by Cariostat at primary dentition and mixed dentition periods, and especially at the beginning of eruption of permanent teeth were effective as index for predicting the caries prevalence at permanent dentition period.
