Abstract
Caries experience in primary teeth has been highlighted as the most important single risk factor for caries development in the subsequent permanent teeth, but at cavitated stages. This 10-year cohort study aimed to evaluate whether children with only initial caries lesions in the primary teeth could also have a higher risk for caries incidence in permanent teeth. We evaluated Brazilian preschoolers aged 1 to 5 years in 2010 (T1) and re-evaluated them 2 (T2), 7 (T3), and 10 (T4) years later. Dental caries in primary and permanent teeth was assessed through the International Caries Detection and Assessment System (ICDAS). For the primary dentition (T1 and T2), the participants were categorized according to caries severity in the first two assessments into children with (i) no caries, (ii) only initial caries lesions (ICDAS scores 1 and 2), (iii) at least one moderate lesion (ICDAS scores 3 and 4), and (iv) extensive caries lesions (ICDAS scores 5 and 6). We also created a dichotomous variable considering only extensive lesions. Demographic and socioeconomic data were also collected. For the permanent dentition (T3 and T4), the participants were re-evaluated for extensive caries lesions after 7 and 10 years of follow-up. The outcome variables were the number of decayed, extracted, and filled surfaces of permanent teeth (D3MFS) and the occurrence of any extensive lesion (caries incidence) after 10 years. Associations were evaluated through negative binomial and Poisson regression analyses, respectively. Incidence rate ratios (IRR) and Relative Risks, along with 95% confidence intervals (95%CI), were derived. At the baseline, 639 children were included, and 429 were reassessed after 10 years (67.2% of retention rate). Children with only initial or moderate caries lesions did not have a higher risk of caries in permanent teeth. By contrast, children with extensive caries lesions were more likely to develop caries in the permanent dentition than children without caries (IRR, 95% CI = 2.90, 1.98 to 4.23). This higher risk was more clearly demonstrated when the caries experience was used as a dichotomous variable (IRR, 95% IC = 4.02, 2.38 to 6.78). In conclusion, children with only initial caries lesions do not have a higher risk of developing dental caries in the permanent dentition by adolescence.