Epidemiological studies of dental caries in groups of Swedish children

Abstract: In a cross-sectional study the extent and distribution of dental caries was studied in 817 children, 4, 8 and 13 years old in three areas inSweden. The importance of dietary habits, sugar intake, social conditions, professional dental care, oral hygiene and the use of fluorides on caries prevalence was analyzed. In a subsample, con­sisting of 88 8-year-olds and 91 13-year-olds the net caries increment during aone-year period was studied.In this longitudinal study, the salivary levels of lactobacllli and S. mutans were determined and correlated to sugar intake and caries increment.The cross-sectional study showed obvious differences in caries preva­lence among the studied areas. These differences could mainly be explained by variations in the age from which children had received professional dental care, frequency of tooth-brushing and the use of topical fluorides. There were no differences in dietary habits or sugar intake that could explain the differences in caries prevalence among the areas studied.Examples are given of how changes in some determinants may affect the caries prevalence by means of path analysis.The longitudinal study showed that caries Increment was higher when sugar intake and meal frequency were high (> the mean value for the age group). The highest mean caries increment was found in children with high prevalence of lactobacllli and S. mutans in the saliva combined with a high sugar intake.Groups of children with high salivary levels of both Iactobac ì II i and S. mutans developed 3-4 times more caries than other children. This relation did not always exist in the Individual case.Children with a low caries Increment during one year (0-2 surfaces) brushed their teeth more often and rinsed their mouths more frequently with fluoride solution than children with a high caries increment (> 3 surfaces). The use of fluoridated toothpaste was somewhat more common, however, in the low carles increment group only in the.8-year-oIds.The gingival status was used as a measure of oral hygiene and gingivitis scores revealed statistically significant differences between groups with a low caries increment and a high carles increment (p < 0.01, p < 0.05) in the two age groups, respectively.With the variables frequency of meals, total sugar intake, salivary level of lactobacilli and S. mutans, oral hygiene and use of topical fluorides the net caries increment during one year could be correctly predicted in 79 % of the 8-year-olds and 81 % of the 13-year-olds when the children were divided Into two groups according to their net car­ies increment; 0-2 surfaces and > 3 surfaces.