Avaliação das propriedades biológicas e físicas de biovidros experimentais para o tratamento da hipersensibilidade dentinária cervical: estudo in vitro e in vivo

Abstract

Objectives: The objective of this work was to evaluate the in vitro and in vivo biological, mechanical and in vivo properties of 2Na2O.1CaO.3SiO2 + 6% P2O5 experimental bioglass containing Sr and K as a therapeutic alternative for the treatment of cervical dentin hypersensitivity (DH). Methods: Three experimental biovessels (BvSr, BvK, BvSRK) were synthesized by the fusion method and were subsequently milled; thus obtaining particles in the micrometer range. The study was divided in three experiments: 1). The potential cytotoxic effect in the 24 and 48 h periods in viability and the morphology using two cell types, NIH / 3T3 line and primary human pulp cell line (CIPH) were evaluated, and the bioglass extract at the concentrations of 5, 50, 100, 500, 1000, 5000 and 10000 μg / ml. 2). The objective of this study was to evaluate the effect of bioglass application on the surface of the bovine dentin in the parameters of surface microhardness (MD), surface roughness (RS), the obliteration capacity of dentin tubules, studying the dentin permeability (PD) field scanning (FEG) electronics and analysis of ionic composition by X-ray dispersive energy (EDS) spectrometry; these parameters were evaluated in the initial dentine bodies (without treatment), after EDTA, after 24 h of treatment and after brushing. 3). The effect of bioglass application on the dentin surface (in vivo) in an animal gingival recession model was studied, after euthanasia of the animals, the ability to adhesion to the dentin surface was verified by FEG and the presence of the ions of the materials by means of EDS. Results: All bioglass maintained cell viability at the lowest concentrations and at concentrations of 5,000 and 10,000 mg / mL exhibited cytotoxicity compared to DMEM. In the physical / mechanical tests on dentin, it was observed that the materials had the capacity to maintain or increase MD and RS, and the ability to reduce PD. In the microphotographs (FEG) the adhesion capacity was visualized on the dentin surface and in the (EDS) it was verified the presence of the different ion characteristic of each material. In the animal gingival recession model, it was possible to verify the adhesion capacity of materials in oral conditions closer to clinical reality. Conclusions: all biovidros showed bicompatibility in cell culture, ability to obliterate the tubules, remineralize dentin in vivo and invitro.