Abstract: Objective: To investigate the effect of quercetin on the human dentin resistance to erosion on in-situ study. Methods: Twenty dentin blocks (2 mm×2 mm×2 mm) were prepared and randomly divided into two groups, which were treated with 1.23×10⁴ μg/mL sodium fluoride and 300 μg/mL quercetin, respectively. The oral environment was simulated through the in-vitro acid and in-situ remineralization cycle. After treated with corresponding solution, dentin specimens were wore by ten volunteers in the customized intraoral appliance. Four cycles of acid etching were performed during this period: soaked in citric acid (pH=2.45) for 4 times with 5 min in each time. The experiment was lasted for 7 days. The SMH and surface profiles were detected before and after erosion by using the surface microhardness tester and contact profilometry, respectively. The SMH% and the surface loss were calculated. Results: In the in situ experiment, all volunteers completed the experiment process. The SMH% of quercetin group was (6.22±2.94)%, which was significantly lower than that of sodium fluoride group [(19.23±5.78)%, P<0.01]. The surface loss in quercetin group [(0.97±0.34) μm] was significantly lower than that in sodium fluoride group [(2.61±0.97) μm , P<0.01]. Conclusion: Based on the in situ experiment, the short-term (2 min) application of 300 μg/mL quercetin solution can significantly improve the acid corrosion resistance of dentin, and the effect is better than the traditional high concentration [(1.23×10⁴) μg/mL] sodium fluoride solution.

Key words: quercetin, matrix metalloproteinase inhibitor, dental erosion, dentin