Correlação entre ICDAS e profundidade da lesão cariosa: Comparação entre estereomicroscopia e radiomicrografia como técnicas de validação

Abstract

Attempts have been made to improve visual diagnosis of caries by including early precavitary and cavitary caries lesions, and the ICDAS ((International Caries Detection and Assessment System) is the one of the most important systems currently in use. ICDAS is validated by a strong correlation with lesion severity (depth) determined by stereomicroscopy (SM), but some aspects of sound dentine under SM can be either sound or carious dentine, raising some concerns with regard to the validation of ICDAS. On this basis, the aim of this study was to test the null hypothesis that both SM and microradiography result in similar correlation between the visual aspect of occlusal caries and its histological severity. 115 occlusal surfaces of human teeth, pre-molars and molars, presenting all ICDAS scores were selected. At each occlusal surface, a specific site was selected for caries diagnosis using ICDAS by two calibrated examiners. Digital microradiography was performed prior to sectioning in order to allow to cut at the site where caries demineralization was deepest. Undemineralized longitudinal tooth sections (~1 mm thick) were prepared and lesion depth was analyzed by two calibrated examiners using both EM and digital microradiograhy after immersing teeth for 24 h in contrasting aqueous solution of potassium and mercuric iodide (Thoulet’s solution with refractive index of 1.47; RxTh). The correlation coefficients between ICDAS and lesion depth were 0.782 (EM) and 0.508 (RxTh), which were statistically significantly different (p = 0.0002; Z test), with a large effect size ?q? of 0.49 (95% CI: 0.641/0.344), and statistical power of 95.7%. For ICDAS cut-off 1-2 with histological threshold D3, the positive predictive value from RxTh (0.58) was higher than that from EM (0.28) (p< 0,00001; effect size h of 0.78, power >99,9%), and the negative predictive value from RxTh (0.72) was lower than that form EM (1,00) (p< 0,00001; effect size h of 1,58, power > 99,9%). In conclusion, the null hypothesis was rejected and histological validation of ICDAS was overestimated by EM.