One hundred years of dental caries in Swedish children and adolescents: a systematic review and data synthesis.

OBJECTIVES: To assess age-specific trends in caries epidemiology among Swedish children and adolescents over the past century and to compare trends between national and non-national data sources. METHODS: A systematic review and data synthesis of published studies, registers, grey literature and archival sources was conducted. Data on the proportion of caries-free individuals and deft/DMFT were extracted for ages 3 to 19 years. Temporal trends were analysed separately for four age groups (3, 6, 12, and 19 years) using log[10]-transformed linear regression models and fractional logit regression. RESULTS: A total of 68 studies, two national registers, and one international register contributed 185 age-specific observations of caries-free status. The proportion of caries-free individuals increased significantly across all age groups (p < 0.001). Improvements were most pronounced among 6- and 12-year-olds, more gradual among 3-year-olds and more modest and variable among 19-year-olds. Trends were comparable between national and non-national data sources except among 3-year-olds, for whom non-national data showed a significantly steeper increase. For 12-year-olds, mean DMFT declined from over 8 in the mid-20th century to below 1 in recent years. CONCLUSIONS: Oral health among Swedish children and adolescents has improved substantially over the past century, although the magnitude and pattern of improvement differed across age groups. Differences in temporal trends between national and non-national data sources were observed among 3-year-olds. CLINICAL SIGNIFICANCE: Age-specific differences in long-term caries trends highlight the need to maintain effective population-based prevention while adapting preventive strategies to age groups in which further improvements remain achievable.