Prevalence and risk indicators for underlying dentin shadows among 12-year-old southern Brazilian schoolchildren

ABSTRACT

Abstract This study aimed to assess the prevalence, extent, and associated factors of underlying dentin shadows (UDS) in the occlusal surfaces of permanent posterior teeth among 12-year-old schoolchildren from southern Brazil. A population-based cross-sectional study that included a representative sample of 1,528 schoolchildren was conducted in Porto Alegre, southern Brazil (participation rate: 83.2%). A questionnaire on sociodemographic characteristics, behavioral habits, and access to dental services was sent to parents/legal guardians of each student selected. Caries examination included the recording of non-cavitated and cavitated lesions, including the presence of UDS, as defined by the ICDAS Group (i.e., a shadow of discolored dentin visible through an apparently intact enamel surface that may or may not show signs of localized breakdown - ICDAS Code 4). The association between predictor variables and UDS prevalence was assessed using survey Poisson regression models. The prevalence of UDS was 6.3% (95%CI = 1.2 -11.3). The mean number of affected teeth among the schoolchildren presenting UDS was 1.51 (95%CI = 1.40 -1.61), ranging from 1 to 6. Type of school (public, PR = 2.23, 95%CI = 1.22 -4.07) and caries experience (DMFT 1-2, PR = 2.41, 95%CI = 1.15 -5.04; DMFT ≥ 3, PR = 3.09, 95%CI = 1.52 -6.27) were significantly associated with UDS prevalence. In conclusion, this population-based cross-sectional study found a low prevalence of UDS in the occlusal surfaces of the permanent posterior teeth of 12-year-old southern Brazilian schoolchildren. Overall caries experience and type of school were associated with UDS in this population.