SUMMARYThe aim of this study was to evaluate by SEM morphological changes of dentin surfaces under the use of 5% NaOCl before applying different acids for etching. In the study, dentin surfaces were prepared from the middle third of 20 non-carious human third molars. Samples were divided into 2 groups with 3 subgroups each. In the first group, no application was performed on dentin surfaces. In the second group, 5% NaOCl was applied for 60 seconds on the dentin surfaces then rinsed with distilled water for 5 seconds. In all of the subgroups, dentin surfaces were etched by different conditioning agents for 15 seconds then rinsed for 30 seconds. After surface applications, all of the specimens were placed in distilled water.
Morphological changes of dentin surfaces were determined by SEM. The results were evaluated by the scoring system based on Brannström et al.In the NaOCl treated groups, scores were as follows: The score of dentin without NaOCl treatment was 0, while it was 4 after phosphoric acid application, 3 after only citric acid-ferric chloride, and 1 after only maleic acid application. In the group where only NaOCl was applied, the score was not exactly 1 but slightly less. The score for NaOCl with phosphoric acid was 4, NaOCl with citric acid-ferric chloride was 3, and NaOCl with maleic acid was 2. Weak acid was found more effective on NaOCl treated dentin surfaces when compared with non-treated dentin surfaces.