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To characterize the behavior of three different polymeric agents before and after an erosive challenge on dentin permeability, to analyze their degradation in both conditions, and to analyze their degree of conversion (DC).The permeability of human dentin disks (1.0 ± 0.2 mm) was measured with smear layer, after its removal, after treatment (LpTreat) with Gluma Desensitizer, PRG Barrier Coat (PBC) or Icon infiltrant (n = 11/group) and after exposure to citric acid (LpEro) (6%, pH 2.1, 1 min). The specimens were analyzed under a Laser Scanning Confocal Microscope (n = 2/group) and the products' DC were calculated. Data were subjected to 2-way repeated measures ANOVA and post-hoc Bonferroni (permeability analysis), to paired t-test (for specimens treated with Icon) and to t-test (DC analysis) (α 0.05).Icon showed the lowest LpTreat and LpEro values, while PBC and Gluma did not differ from each other under these conditions. Icon and PBC showed LpEro similar to a dentin with smear layer. Under the Laser Scanning Confocal Microscope, more deposits were noticeable on dentin after treating with PBC. Gluma presented the deepest penetration in dentin. The DC of PBC was the highest.Icon caused the highest reduction on permeability values, followed by PBC and Gluma. PBC generated more deposits covering dentin and seemed to be more efficient after an erosive challenge. The association of a polymeric resin with inorganic ion-releasing fillers seem to be a great strategy to manage dentin hypersensitivity under erosive conditions.

This study evaluated the protective effect of TiF

Objectives This study evaluated the erosive tooth wear promoted by commercial whitening toothpastes on eroded dentin in vitro. Design Ninety bovine roots were embedded, polished and subjected to the baseline profile analysis. The samples were protected in 2/3 of the dentin surface and were randomly assigned to 6 groups (n = 15/group): Oral-B 3D White; Close-up Diamond Attraction Power White; Sorriso Xtreme White 4D; Colgate Luminous White; Crest and erosion only. All samples were submitted to erosive pH cycles (4 × 90 s in 0.1% citric acid, pH 2.5, per day) and abrasive challenges (2 × 15 s, per day) for 7 days. The samples were subjected to abrasion, using toothbrushing machine, soft toothbrushes and slurries of the tested toothpastes (1.5 N, 1:3 water). Between the challenges, the samples were immersed in artificial saliva. The final profile was overlaid to the baseline profile for the calculation of the erosive dentin wear (μm). The data were subjected to Kruskal-Wallis/Dunn tests (p Results Colgate Luminous White (4.7 μm) and Sorriso Xtreme White 4D (4.0 μm) promoted the highest wear, similarly to Oral-B 3D White (2.3 μm). Oral-B 3D White promoted similar wear compared to Crest (1.1 μm) and Close-up Diamond Attraction Power White (1.2 μm); however, it induced significant higher dentin wear compared to erosion only (1.0 μm). Close-up Diamond Attraction Power White and Crest did not increase the erosive wear compared to erosion only. Conclusion Some whitening toothpastes increase the wear of eroded dentin, which should be considered by the dentist when prescribing them to patient with root exposure.

This study evaluated the protective effect of TiF4 varnish, after pre-treatment with proantocyanidin or chlorhexidine, on the progression of erosive dentin loss (EDL), under the presence or absence of the demineralized organic matrix (DOM). Bovine root dentin samples were eroded for 30 min (0.1% citric acid, pH 2.5) and the loss was measured by profilometry. Half of them were subjected to the DOM removal using collagenase for 4 days, while the other half remained immersed in water. The removal of DOM was checked by profilometry. Samples were divided into 24 groups (n = 15) according to the factors: 1– With or without DOM; 2– Pre-treatment with 0.012% chlorhexidine gel, 10% proanthocyanidin gel or untreated for 1 min; 3–Final Treatment with TiF4 varnish, NaF varnish, placebo varnish or untreated for 6 h. The samples were submitted to a pH cycling for 5 days: 0.1% citric acid (4 × 90s/day) and artificial saliva between the challenges. The final profile was obtained for the calculation of EDL (μm, three-way ANOVA/Tukey test). When DOM was preserved, the EDL was lower compared to the condition without DOM (7.08 ± 4.03 μm and 9.80 ± 3.79 μm, p

To compare the effect of 5 desensitizing agents on the hydraulic conductance (Lp) of dentin and to analyze its surface under a Laser Scanning Confocal Microscope (LSCM) before and after an erosive challenge.Lp was analyzed in the following sequence: in the presence of smear layer (pMin), after a 15-second acid etching (pMax), after treatment with a desensitizing agent (pTreat) and after a 1-minute erosive challenge (6% citric acid - pEro). Fifty 1.0 ± 0.2 mm-thick dentin disks were prepared from sound human third molars and were randomly distributed into 5 groups (n = 10): FG-Fluoride gel (control), SA-Sensiactive, PR-Sensitive Pro-Relief, NP-Desensibilize Nano-P and EV-Enamel Pro Varnish. Data were analyzed by two-way ANOVA and Tukey tests (α0.05). Additional specimens were analyzed under a Laser Scanning Confocal Microscope (LSCM) and by Energy Dispersive X-ray Spectroscopy (EDS).All materials reduced the Lp in some extent, except for FG and EV. After the erosive challenge, SA was the only material effectively able to keep the same Lp of the post-treatment phase, while the other products showed lower resistance upon an erosive challenge. Under the LSCM, the SA and NP materials were more effective to obliterate the opened dentin tubules and demonstrated higher resistance upon an erosive challenge. The EDS analysis evidenced levels of Ca, O, P, Si, Na and S.Product containing potassium oxalate was the most effective in reducing Lp of dentin samples before and after an erosive challenge. Under a LSCM, products containing potassium oxalate or hydroxyapatite crystals seemed to be occluding the dentin tubules after an erosive challenge.