Análise in vitro da resistência fluxural de uma resina composta direta e uma resina laboratorial de segunda geração associadas ou não a fibras de reforço

Abstract

The present study aims to evaluate in vitro the flexural strength of the direct composite resin (FiltekTM Z-250 – 3M/ESPE) and of the second generation laboratory resin (CeseaDST II – Kuraray) either associated or not to glass fibers (Fibrex-coronal – Angelus), varying the source of photoactivating (L.E.Demetron 1 – Kerr e Strobolux – EDG). Fifty-six samples were made inside a biparted metalic matrix, 13.0 mm in diameter X 2.4 mm thick, divided into 8 study groups (n=7): GI – Resin FiltekTM Z-250/ Fibreless/ LED; GII – Resin FiltekTM Z-250/ Fibreless/ Strobolux; GIII - Resin FiltekTM Z-250/ Fibrex-coronal/ LED; GIV - Resin FiltekTM Z-250/ Fibrex-coronal/ Strobolux; GV – Resin CeseaDST II/ Fibreless / LED; GVI - Resin CeseaDST II/ Fibreless / Strobolux; GVII - Resin CeseaDST II/ Fibrexcoronal/ LED; GVIII - Resin CeseaDST II/ Fibrex-coronal/ Strobolux. The samples were under the test of biaxial flexural strength in the Kratos equipment, with speed of 1 ± 0.5 mm/min and load cell of 500 Kgf. The flexural strength values were submitted to the Tukey test (P=0,01). The rate of the results in MPa were: GI – 187.91 ± 32.78; GII – 196.76 ± 31.15; GIII – 208.27 ± 18.79; GIV – 218.02 ± 15.76; GV – 101.72 ± 11.25; GVI – 103.05 ± 9.56; GVII – 164.76 ± 12.54 e GVIII – 176.75 ± 47.03. The conclusion is that the analyzed composites showed different behaviors in vitro; the direct composite FiltekTM Z-250 showed higher values of flexural strength in all the studied groups; the type of light source did not interfere in the flexural strength of the evaluated composites; reinforcement with fibers increased the flexural strength both evaluated composites, however only for the indirect composite CeseaDST II that increase was significant.