Efecto de la energía de polimerización sobre la sorción acuosa y solubilidad en composites envejecidos por UV

Abstract

The chemical degradation of the organic matrix favored by water sorption and solubility affects the physical and mechanical properties of dental resin composites and could commit the restoration longevity. The objective of this study was to evaluate the water sorption and the solubility in dental resin composites at different times of accelerated aging by UV. Specimens were manufactured with different energy densities. Four commercial dental resin composites were included in the study: F. Z-250, F. Supreme (3M ESPE), Tetric Ceram and Tetric EvoCeram (Ivoclar Vivadent). For each one, 60 specimens were made following the procedure indicated by ISO 4049 Std, divided in three groups: A (3.75 J/cm²), B (9 J/cm²), C (24 J/cm²), and subdivided in: 1(no aging), 2 (500 hours of aging), 3 (1000 hours of aging) and 4 (1500 hours of aging). The results were analyzed by means of ANOVA and Tukey tests (α = 0.05) to determine the effect of the factors. The energy density stops to be relevant factor after 500 h of aging. As the time increases under aging, the water sorption and the solubility decreased. The Water Sorption results were: 0 h (21.5 μg/mm³), 500 h (17.9 μg/mm³), 1000 h (18.2 μg/mm³), 1500 h (15.8 μg/mm³); the Solubility ones were: 0 h (0.9 μg/mm³), 500 h (1.0 μg/mm³), 1000 h (0 μg/mm³) and 1500 h (-1.3 μg/mm³).