The role of bioactive, resinous and fluoridated agents in the treatment of dentin hypersensitivity and their interaction with sound and eroded dentin: in vitro and clinical studies

Abstract

Dealing with dentin hypersensitivity treatment faces the challenge to reach a long-term relief effect. Searching for innovation implies in feasible strategies, which require the analyses of their mechanism (physical-chemical) and translation to clinical scenario. The objective of this work will be to evaluate, under different aspects, the action of a glutaraldehyde-based desensitizer (Gluma® Desensitizer Power Gel) and a vehicle containing the S-PRG Giomer technology (S- PRG Barrier Coat®) compared to essentially chemical technologies: a 5% fluoro-calcium phosphosilicate-based toothpaste (BioMin F®), an amine fluoride, tin chloride and chitosan-containing toothpaste (Elmex Erosion Protection®), a fluoride varnish with 5% NaF (2,26% of F, Duraphat®) and a fluoride varnish containing TiF4 at 4% (2,45% of F). In vitro physicochemical properties and clinical performance will be evaluated to verify their mechanisms of action and interaction with dentin. Initially, the materials will be chemically characterized by X-ray spectroscopy (EDX) and a 3¼L aliquot will be analyzed by Fourier Transform Infrared Spectroscopy (FTIR) for analysis of the interaction of these materials with sound and artificially eroded human dentin. The Degree of Conversion (DC) analysis of the SPRG Barrier Coat® will also be analyzed. Then 1±0.2 mm-thick dentin discs will be analyzed before and after application of these materials to evaluate the reduction of dentin hydraulic conductivity (Lp) in the Flodec device. Finally, BioMin F® and Elmex Erosion Protection® toothpastes will be applied in a randomized controlled clinical trial in DH patients for three weeks and compared to a 5% NaF (Duraphat®) varnish, to a 4% TiF4 varnish and to each other for 1 and 3 months. Data will be analyzed for normality and homogeneity (Kolmogorov and Smirnov test and Bartlett test, respectively) and, if approved, will be subjected to appropriate parametric tests. Otherwise, they will be analyzed using nonparametric tests, followed by appropriate post-hoc tests. In all cases, the significance level will be set at 5%. (AU)