Ultramorphology and dentine permeability changes induced by prophylactic procedures on exposed dentinal tubules in middle dentine

Abstract

The purpose of this study was to evaluate the changes in dentinal permeability (i.e. hydraulic conductance) after prophylactic treatment performed using prophy-powders with air-polishing system or prophy-pastes applied on exposed middle dentine. The changes in dentine morphology were evaluate by SEM. Several prophylactic pastes or air-polishing powders were tested in this study. Dentine discs from human third molars were used to study the quantitative reduction of the dentine permeability under simulated pulpal pressure (20 cm H₂O). Further specimens were gold-coated and observed with the use of a SEM. The results of this study showed different reductions of dentin permeability effects based on the type of product employed (i.e. prophylactic paste or air-polishing powders). The use of Sylc bioactive glass and sodium bicarbonate were the most effective in reducing dentine permeability of the specimens etched with the phosphoric. The air-polishing procedures performed with Sylc bioactive glass created a dentine surface devoid of exposed dentinal tubules due to the presence of a compact multilayered smear layer. Colgate Sensitive Pro-Relief and Nupro NU-Solution reduced the dentine permeability up to 69.8% and 66.9% respectively. Although all the tested products are able to statistically reduce dentine permeability, Sylc bioactive glass is an innovative and effective product suitable for the reducing of the dentine permeability during prophylactic procedures of air-polishing.