Clinical diagnosis of occlusal dentin caries

An occlusal restoration is usually considered necessary when a lesion extends into the dentin. This study aimed to assess the relationship between the clinical appearance of occlusal caries and the lesion depth. Special attention was paid to differentiate the inner, partly demineralitzed layer of carious dentin that should be preserved from the outer carious layer that should be removed before placing a restoration. Fissures in extracted premolars and molars were classified clinically by the authors. The mean pairwise interobserver agreement, weighted Cohen's kappa (kappa), was 0.73, which indicated 'substantial agreement'. The depth of zones revealing softness by probing and/or discoloration was assessed on ground surfaces. Of the carious fissures that were scored sound by clinical examination (n = 17), 76% revealed enamel lesions on the ground surfaces. Of those occlusal surfaces with a discoloration only but no cavitation (n = 57), 13 showed dentin lesions, but only 5 of these revealed softness by probing. Of those lesions with very small cavitations (n = 60), 19 were confined to enamel, 41 showed dentin lesions and of these 32 revealed softness by probing. All but 1 of the lesions with small cavitations (n = 28) showed dentin involvement and all but 2 of these revealed softness. If cavitation in the occlusal lesion was used as a criterion for identifying dentin lesions with softness, the sensitivity and specificity values were 0.92 and 0.69, which means a relatively high frequency of overregistration.