Efeito da composição do infiltrante e da zona histológica sobre a variação na microdureza do esmalte cariado infiltrado exposto a degradação em água

Abstract

The present study aims to evaluate microhardness in bovine teeth with artificial caries lesion, submitted to resin infiltration with different compositions, before and after hydrolytic degradation. Four groups of 26 samples with different monomeric compositions were formed: 1 - Commercial control; 2 - TEGDMA, UDMA, HEMA; 3-TEGDMA, HEMA; 4 - TEGDMA, BisEMA. Bovine enamel blocks (5x5mm) were used forinduction of artificial caries, and then analyzed in radiomicrography for the certification of caries lesions. Afterwards, the samples were submitted to resin infiltration, according to the group to which they belonged. The sample was then cut in half, preserving a healthy area and infiltrated area for posterior cross-sectional analysis in a microdurometer, with a load of 200g for 10s, at 30 and 90μm of the surface. The specimens were placed in distilled water for 21 days, and microhardness analysis was performed again, with the same parameters. Finally, fluorescence microscopy was performed on all samples to evaluate the homogeneity of the infiltration. All groups presented normal distribution. The infiltrator 4 (TEGDMA + BisEMA) resulted in a lower microhardness variation after immersion in water than the other infiltrators, with a great magnitude of effect (g of Hedge from 0.83 to 1.19) and high power (from 84% to 99%), with no difference between depths. It was verified that composition of the resinous infiltrate interferes in the alteration of the microhardness of the infiltrated enamel exposed to water. Enamel microhardness was not influenced by histological zone and its interaction with resin composition.