Efeito in vitro de diferentes protetores de superfície na rugosidade de cimentos de ionômero de vidro após desafio cariogênico

Abstract

The Glass Ionomer Cement (GIC) is a widely used material in dentistry; however, because of its vulnerability to syneresis and imbibition, the use of surface protectors to isolate its surface has been recommended. Although, very few studies have evaluated the effects on the GIC surface after using protection and being through a cariogenic challenge.The aim of this work was to investigate the effect of the cariogenic challenge with pH cycling on the surface roughness of a conventional GIC (Riva Self Cure) and a resin modified one (Riva Light Cure), with three different surface protectors (varnish, adhesive and Riva Coat).Eighty samples (4 x 2 mm) were prepared according to the manufacturers’ recommendations, with 40 being Riva Self Cure, and 40 Riva Light Cure, which were split in 8 groups according to the kind of surface protector applied: Riva Coat, Scotchbond adhesive, Varnal varnish and a control group without protection. The protectors were applied with a microbrush. The samples were submitted to the initial roughness measurements (Ra) and next to the pH cycling (35mL in demineralization solution for 3h and in 18mL of remineralization solution for 21h) during 7 days. Afterwards, the final Ra measurement of the samples was performed. The data were analyzed by the paired Student T test, Anova One-Way and Tukey, with α=0,05. The Ra values from all of the groups increased after the cariogenic challenge, except the Riva Light varnish group, that did not show any significant difference in the Ra values before and after the challenge. There were no differences in the Ra values among the groups of protectors of Riva Self, both before and after the challenge. Regarding the Riva Light protectors, the varnish group presented higher Ra in comparison to the control and adhesive groups, however after the challenge there was no statistical difference between them. Finally, it can be concluded that despite the use of surface protection, there was an increase on the values of surface roughness of both glass ionomer cements used, after de cariogenic challenge.