Effect of oxygen plasma on dentin exposed to NaOCl

Abstract

Introduction

Plasma treatment is an effective technology since the internal properties of the material is kept unchanged after treatment, modifying only the surface.

Objective

To evaluate the effect of oxygen plasma on dentin previously exposed to 6% NaOCl.

Material and method

60 bovine incisors were used. The crown was removed, the root splited and the faces planned amounting 120 segments related to the cervical third. The samples were divided into 2 groups, control (immersed in 6% NaOCl, washed with distilled water, dried, immersed in 17% EDTA, washed and dried) and oxygen plasma (after treatment described in the control group, oxygen plasma was applied for 30s). The samples were evaluated qualitatively in relation to topography by scanning electron microscopy using photomicrographs at 1000× of magnification. The Ramé-hart goniometer was used to measure the contact angle between the surfaces and the following solutions: water, ethyleneglycol, and diiodomethane. Then, surface energy, polar and dispersive components, was calculated. Additionally, it was evaluated the flow of Pulp Canal Sealer EWT (PCS) and Real Salt SE (RS) sealers on dentin surface. Data were statistically analyzed using Kruskal-Wallis e Mann-Whitney U (p<0.05).

Result

Plasma treatment caused topographical changes on dentin surface. This treatment led to an increase in surface energy and polar component, favoring the hydrophilicity of the surface. However, it disfavors the wettability of PCS and did not influence the RS wettability.

Conclusion

The oxygen plasma caused topographical changes on dentin surface, favoring its hydrophilicity. However, it did not favor the sealers wettability on dentin.

Descriptors:
Plasma gases; sodium hypochlorite; topography; surface properties; wettability