Radiographic pattern of underlying dentin lesions (ICDAS 4) in permanent teeth

To assess the radiographic pattern of underlying dentine shadows (UDS) in the occlusal surfaces of permanent teeth.

A total of 282 permanent posterior teeth pertaining to 91 individuals, 142 UDS and 140 non-cavitated enamel lesions (NCEL), were included for comparison. UDS was defined as shadows of discolored dentin visible through the enamel surface which may or may not show signs of localized enamel breakdown, classified as code 4 by the International Caries Detection and Assessment System group. Data collection included the application of a questionnaire, clinical examination, and bilateral bitewing radiographs. The risk for presenting radiolucency was estimated using logistic regression model with generalized estimating equations.

Approximately 79% of UDS exhibited no radiolucency. The proportion of teeth exhibiting a radiolucency restricted to the enamel-dentin junction was 20.4% for UDS and 3.6% for NCEL (p < 0.001, chi-square test). UDS had a sixfold increased risk for exhibiting radiolucency compared with NCEL (OR = 5.78, 95% CI = 2.73-12.22, p < 0.001). Despite this finding, it is important to highlight that virtually all cases were located at the enamel-dentin junction, and only one tooth in each category of clinical status exhibited radiolucency at the outer one half of dentin. No tooth exhibited radiolucency reaching the deep dentin.

The present study showed that UDS presented radiolucency in very few cases. The vast majority of lesions showed no radiolucency.

Our findings suggest that only a small proportion of UDS would demand restorative treatment.