Caries experience between primary teeth at 3–5 years of age and future caries in the permanent first molars

Background/purpose: Past caries experience remains the most powerful predictor of future caries. This study was aimed at exploring the possible relationship between the caries statuses at 3–5 and 8–10 years of age and examining the predictive power of caries experience at 3–5 years of age for the caries pattern at 8–10 years of age. Materials and methods: A total of 76 children (43 boys and 33 girls) were included in this study from 2012 to 2018. The first caries examination, performed in 2012, was completed when participants underwent dental rehabilitation under general anesthesia at 3–5 years of age. Tooth decay was recorded based on the International Caries Detection and Assessment System criteria. The caries examination was repeated in the clinic in 2018 when the participants were 8–10 years old. Associations between the permanent and primary teeth were analyzed using the Mann–Whitney U test. The receiver operating characteristic curve analysis was performed to determine the predictive accuracy of the primary dentition. Results: A significant dmfs score of the primary second molar was found between groups of free dentin caries and dentin caries of the permanent first molars (p = 0.002). The calculated areas under the receiver operating characteristic curve for the dmfs score of the primary second molar was 0.74. Conclusion: Caries in the primary second molars is a clinically useful predictor at 3–5 years of age for future dentin caries development on surfaces of the first permanent molars in the following 5 years.