Characterization of dentin morphology after application of ozone and sodium ascorbate by scanning electron microscopy and atomic force microscopy

Resumo

The aim of this study was to evaluate dentin morphology after ozone gas and sodium ascorbate application by the Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) images. Material and methods: Seven freshly extracted human third molars were sectioned perpendicularly to the tooth long axis, 3mm above the cementoenamel junction and other section above the first. Dentin slices were obtained, 2 mm thickness, then the slices were sectioned vertically and horizontally into four equal parts, resulting in 28 samples. These were divided in 4 groups (n=7): (G1) phosphoric acid – control; (G2) ozone + phosphoric acid; (G3) phosphoric acid + ozone; and (G4) ozone + sodium ascorbate + phosphoric acid. Dentin morphology of six samples of each group
was evaluated by SEM and one by AFM. Results: In Groups 2 and 4 there was a change in the effectiveness of acid etching in terms of removing the smear layer. In Group 3 there was a change in the dentin microstructure, which can be a harmful factor regarding the bond strength of adhesive agents. Conclusion: After the qualitative analysis, the application sequences of ozone, phosphoric acid etching and sodium ascorbate application generated differences in the dentin
morphology by SEM and AFM. Sodium ascorbate decreased the ozone effect before the acid etching but did not eliminate it.