EVALUATION OF ROUGHNESS AND MICROHARDNESS OF ERODED ENAMEL TREATED WITH RESINOUS INFILTRANT CONTAINING AMORPHOUS CALCIUM PHOSPHATE AND SUBMITTED TO ABRASION.

Abstract

This study proposes to evaluate the surface roughness and microhardness of eroded enamel treated with an experimental resinous infiltrator containing 2% amorphous calcium phosphate and subjected to simulated brushing. For this study, enamel/dentin samples will be made from healthy human third molars, which will be randomly assigned to three different treatment groups (n=20): G1 - Commercial Infiltrant, G2 - Experimental Infiltrant and G3 - Artificial Saliva and, stored in eppendorfs under relative humidity. Prior to the treatments, the samples will undergo a simulation of intrinsic erosion, where they will be immersed in demineralizing solutions (DES), composed of 0.01 M HCl (pH 2.3), for 2 min, and remineralizing solutions (RE), composed of 150 mM KCl, 1.5 mM CaCl2, 0.9 mM KH2PO4, 0.1 M Tris (pH 7.0), for 60 min. Four cycles per day will be performed for 5 days. After that, the samples will be submitted to resin infiltration and exposure to artificial saliva, according to each group. The analyses of surface roughness and microhardness will be performed in 4 different times: time I - healthy enamel, time II - eroded enamel, time III - post-treated enamel, and time IV - treated enamel after simulated brushing. For the simulated brushing, a mass of 8g of a dentifrice mixed with 24ml of distilled water will be used for each sample, forming a slurry (1:3). It will be performed 10.000 mechanical brushing cycles, with a frequency of 4 Hz, at 37o± 0.5oC, under a load of 200 g to simulate the force used during brushing. The results will be submitted to homogeneity and normality tests to be further analyzed by the most appropriate test, considering a 5% significance level.