Profundidade de polimerização de um compósito com matriz de silorano

Abstract

This study evaluated the influence of different curing times in the depth of cure of two different composites. The silorane-based composite, Filtek P90, was compared with compared with the methacrylates-based composite, Filtek Z250. Specimens were divided into four groups varyng type of material and polymerization time in seconds, respectively: (G1) - Z250, 20, (G2) - Z250, 40 (G3) - P90, 20, and (G4) -P90, 40. Specimens were cured with a 1400mW/cm2 LED (RadiiCal). These were embedded in epoxy resin and worn longitudinally by half the diameter in order to measure the Knoop Hardeness in three different depths: top, 1.25 mm and botton of specimens. Data were analyzed by two-away ANOVA test for multiple comparisons, the Student - Newman-Keuls test with p= 0.05. The depth did not significantly affect the hardeness of Z250 composite (p = 0.8338) and P90 (p=0.1578). Curing time was not significant in the hardness of Z250 (p=0.4602), but influenced P90 (P=0.0407), with significantly higher values for G4. It was concluded that the composite of low shrinkage requires more time for curing to obtian high values of hardness then the dimectilate composite and, tha both composites have adequate values of Hardness on 2.5 mm depth of cure.