Análise de alterações em cimentos de ionômero de vidro indicados para o tratamento restaurador atraumático submetidos à ação de escovas dentais de diferentes texturas

Abstract

This in vitro study was conducted to test the potential for abrasion toothbrush bristles of soft to medium texture in different glass ionomer cements indicated for atraumatic restorative treatment (ART). The evaluation of the abrasion caused by brushing was performed using three parameters: change in mass, roughness and surface hardness. We evaluated two ionomer glass of high viscosity (Ketac™ Molar Easymix/ 3M Espe and Vitro Molar®/ DFL) and a conventional (Bioglass R®/ Biodinâmica), as positive control was used microhybrid composite resin (Z100™/3M Espe). After making 20-specimens of each test material, they were divided into two subgroups, those submitted to bristle toothbrushes soft and medium texture. The weights were obtained after consecutive weighings to stabilize. The surface roughness was determined by the average of five readings of the value of the arithmetic average surface roughness (Ra) in specimens, and microhardness was obtained by averaging five indentations with a load of 100 grams (g) for 20 seconds (s ), determining the value of Vickers hardness (HV). Having determined the values of three parameters, the specimens of each group were submitted to 20.000 brushing cycles with toothbrushes bristle texture specific to each group. Obtaining mass, roughness and hardness was reached just as thinitial values. The data were statistically analyzed by Student T test and ANOVA with post-Tukey test (p <0.05). It was found that both materials will wear out after brushing, increasingly, being Z100TM composite resin material with lower wear, followed by cement glass ionomer Ketac™ Molar Easymix, Vitro Molar® and Bioglass R®. The ionomer glass of high viscosity with the lowest value of surface roughness both initial and final was the Ketac™ Molar Easymix with a mean value of 0,50 μm being statistically different from the other ionomer glass and lower the value of the material control. Ketac™ Molar Easymix also showed the highest value of hardness (64,85), and was significantly higher than the other glass ionomer. The difference in the texture of the bristles of the toothbrush did not cause wear different.