Sombreamentos em dentina (lesões de cárie ICDAS 4) em dentes permanentes posteriores

Abstract

The present dissertation is composed of two manuscripts whose objectives were to analyze the prevalence, extension, and risk indicators associated with dark shadows from dentin (ICDAS 4) in 12-years-old schoolchildren from Porto Alegre, RS (Article I) and to evaluate the radiograph pattern of dark shadow from dentin (ICDAS 4) in the occlusal surfaces of permanent posterior teeth compared to dark non-cavitated lesions (ICDAS2) (Article II). Article I is linked to an epidemiological survey conducted to assess the oral health conditions of a representative sample of 12 year-old schoolchildren from Porto Alegre, RS (n=1,528). Data collection included the application of a questionnaire and clinical examination. The primary outcome of the study was the prevalence of dark shadow from dentin in permanent teeth. Poisson regression models were used to assess the association between predictor variables and the prevalence of dark shadows from dentin. The second study was conducted on a convenience sample selected in Santa Maria, RS. In addition to a questionnaire and clinical examination, data collection included bilateral bitewing radiographs. The radiographic expression of dark non-cavitaded lesions (ICDAS 2, n=140) and dark shadows from dentin (ICDAS 4, n= 142) was compared using the chi-square test. The risk of presenting radiolucent image in dentin was estimated through logistic regression models with generalized estimating equations to adjust for clusters. In article I, the prevalence of dark shadows from dentin lesions was 7.4% (95%CI [confidence interval]=2.8-12), corresponding to 117 students. The adjusted model showed that type of school (public, PR [prevalence ratio]=2.05, 95%CI=1.16-3.65, p=0.01) and caries experience (DMFT 1-2, PR=2.22;95%CI=1.08-4.57, p=0.03; DMFT≥3,PR=3.26;95%CI=1.41-7.53, p=0.01) were significantly associated with the prevalence of dark shadows from dentin. In article II, it was observed that the majority of lesions presented no radiographic image (87.2%) or, when present, the image was restricted to the enamel-dentin junction (12.1%). The proportion of cases with radiographic image at the enamel-dentin junction was significantly higher in dark shadow from dentin than in dark non-cavitated lesions (p<0.001). However, only one case in each group presented an obvious image in dentin. In the risk analysis, dark shadows from dentin had a 6-foldincreased risk for presenting any radiolucent image in dentin compared to dark non-cavitated lesions (odds ratio=5.78, 95%CI=2.73-12.22, p<0.001).