Efficiency of cavitary varnishes containing experimental bioglass particles in the occlusion of dentinal tubules.

This research aims to evaluate the efficiency of cavitary varnishes containing experimental bioglasses in the occlusion of dentinal tubules. One hundred and sixty-eight cervical buccal dentin samples were obtained from bovine teeth. Samples were randomized into the following groups: I. Distilled Water (DW); II. Cavity Varnish (CV); III. Colgate^® Sensitive Pro-Relief™ (CS); IV. 45S5 Bioglass (45S5); V. KSr Bioglass strontium potassium (KSr); VI. P Bioglass phosphorus (P); and VII. PSi Bioglass phosphorus silica (PSi). The treatments were applied to the surfaces of the samples, which were then subjected to simulated brushing. The samples were analyzed for a) characterization of bioactive glasses; b) surface roughness; c) descriptive analysis of the dentin surface; d) total versus occluded number of dentinal tubules; e) diameter of the dentinal tubules; f) chemical composition of the dentin surfaces, and g) dentin permeability. All groups treated with biomaterials without the brushing challenge showed an increase in roughness and (total or partial) occlusion of the dentinal tubules. The PSi group had the best values for occlusion, while the KSr group had the highest calcium and phosphorus concentrations. After the brushing challenge the roughness was controlled by the presence of biomaterials; 45S5, KSr, and PSi showed occlusion of the dentin tubules. All bioactive glasses showed reduced tooth permeability compared to distilled water. The PSi group had the smallest tubule diameter and highest phosphorus concentration. KSr and PSi bioglasses are promising materials for dentin occlusion and remineralization and are promising new biomaterials for the treatment of dentin hypersensitivity.