Dentinal hardness after caries removal: evaluation of different methods

Abstract

The purpose of this study was to evaluate the Knoop microhardness of remaining dentin in deciduous teeth, after three different methods of caries removal, in vitro. Fifteen extracted or exfoliated primary molars with moderate interpro- ximal carious lesions were used for the study. Each tooth was sectioned longitudinally through the lesion in order to obtain 30 hemi-sections. Caries removal was performed in each group of 10 hemi-sections, as follows: 1) mechanical removal (low speed – stainless steel bur) using an explo- rer to evaluate the hardness of the remaining dentine; 2) mechanical removal (low speed – stainless steel bur) using a caries detection dye (Caries Detector); 3) chemo-me- chanical method (Carisolv). Methods 2 and 3 were performed following the manufacturers’ instructions. After caries removal, all cavities were filled using an adhesive system (Single-Bond - 3M Espe) and composite resin (Z250 – 3M Espe). Microhardness indentations were performed at 150 and 300 mm from the enamel-dentine junction at 3 different locations with 100 mm intervals from the tooth- restoration interface. Statistical analysis (ANOVA and Tukey’s test) showed no significant difference (p > 0,05) between the mean hard- ness of groups 1 and 2 and both values were significantly higher (p < 0,05) than values for group 3. It was concluded that caries removal through the new chemo-mechanical method preserved more dentinal structure than the two other me- thods tested. Key words: dentin, caries remo- val, hardness.