Effect of Surface Protection Agents on the Control of Erosive/Abrasive Wear

Objectives: The aim of this study was to evaluate the protective effect of different resin-based coating materials, applied over eroded enamel, against erosive and abrasive wear.
Methods: Bovine enamel specimens were demineralized with 0.3% citric acid (pH 2.6 - 5min) to simulate the initial erosion lesions and randomly assigned into six groups, according to the surface treatment (n=20): ICON – Resin infiltrant (RI) (Icon - DMG); IconNE - RI without previous acid etching; FU – Self-etching adhesive system (Futurabond U - Voco); CLI – glass ionomer varnish (Clinpro XT Varnish - 3M/ESPE); PGR - light-cured S-PRG varnish (PRG Barrier Coat - Shofu); CO - control group (ultrapure water). The thickness of the materials layers were evaluated. After that, a 5 days erosive/abrasive challenge was performed, consisted of 5 min immersion in 0.3% citric acid, toothbrushing (600 strokes/day) and storage in artificial saliva in the intermediate periods. Surface wear was evaluated by contact profilometry. The data were analyzed by ANOVA and Tukeys test (alfa = 5%).
Results: Significant differences on layer thickness were observed after the application (p=0.0001): CO – 0.001(0.01)^a, ICON – 1.00(5.61)^a, IconNE – 4.41(0.81)^a, FU – 16.07(2.77)_^b, CLI – 21.00(4.48)^bc, PGR – 23.12(3.85)^c. Significant differences in surface wear were observed (p=0.0001): CO – 56.15(46.45)^a, ICON – 66.59(7.75)^b, IconNE – 139.77(12.32)^c, FU – 23.60(1.95)^d, CLI – 12.51(7.54)^e, PGR – 16.93(5.19)^e.
Conclusions: The varnishes PRG Barrier Coat and Clinpro produced thicker layer than the other materials and the highest erosion protection. The adhesive Futurabond and the infiltrant Icon with acid etching showed significant protection effect, but smaller than the varnishes tested.