Avaliação do desgaste e da alteração da rugosidade superficial em resinas compostas de diferentes características submetidas à escovação simulada e ciclagem de pH / Wear and surface roughness alteration evaluation of different composite resins after toothbrushing and pH cycling

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

29/08/2011

RESUMO

The present study aimed to quantitatively evaluate the surface roughness alteration and wear of resin composites with different characteristics of organic matrix and inorganic filler when submitted to simulated toothbrushing abrasion and pH cycling. Three different resin composites were evaluated: Filtek Z250 (Bis-GMA, microhybrid), Filtek Z350 (Bis-GMA, nanofilled) and Filtek P90 (silorane based, microhybrid) (3M-ESPE). For each resin two groups (n=10) of rectangular specimens (15mmX5mmX4mm) were made. After polymerization and polishing, the initial roughness (Ra) was evaluated by the average of three tracings using a roughness tester Hommel T1000 basic. Half of each specimen was protect with nail varnish and one group of each resin was submitted to pH cycling (demineralization-pH 4,3 and remineralization-pH 7,0). For the abrasion test 100.000 strokes of simulated toothbrushing was processed. The protected side was maintained as control. Over the brushed side the final roughness was measured with the same initial parameters and wear was quantified by the average of 3 readings of the real profile between the two surfaces (control and brushed side). The obtained results (ANOVA, Student t test and Tukey, p<0.05) showed significant differences of wear and surface roughness alteration between the tested materials. Filtek P90 presented the highest average wear rate (11.505 ± 5.690µm) compared to Z250 (4.191 ± 1.725µm) and Z350 (4.163 ± 0.947µm) and the pH cycling significantly affected the wear of Filtek P90(15.305 ± 5.409 mM). The surface roughness evaluation revealed an increasing on surface roughness for Filtek Z250 and Filtek Z350 after toothbrushing, while Filtek P90 showed an opposite behavior, with statistically significant differences (p<0.05). The scanning electron microscope images were in accordance to the quantitative results obtained.

ASSUNTO(S)

desgaste roughness rugosidade silorane silorano wear

ACESSO AO ARTIGO

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