Exothermic Behavior, Degree of Conversion, and Viscoelastic Properties of Experimental and Commercially Available Hard Chairside Reline Resins

Abstract

This study evaluated the exothermic behavior, degree of conversion (DC), and the viscoelastic properties of five reline resins, two experimental (E1 and E2), and three commercially available (Kooliner, K; New Truliner, NT; and Tokuyama Rebase II, TR II), and one denture base resin (Lucitone 550, L). The exothermic behavior was assessed (n = 4) using a type-K thermocouple. The DC (%) was measured (n = 5) by Fourier transformed infrared spectroscopy-attenuated total reflectance (FTIR-ATR) spectroscopy. The viscoelastic properties were evaluated (n = 2) by dynamic mechanical thermal analysis (DMTA) under different runs. Storage modulus (E') and loss tangent (tan delta) at 37 degrees C were obtained from the first and last runs. The glass transition (Tg) was measured from the last run. Data were analyzed by analyses of variance (ANOVA) and Tukey tests (alpha = 0.05). K and NT produced similar peak temperature to TR higher than E1 and E2. E1, E2, and TR II showed the lowest time to peak temperature. NT produced the highest DC, followed by TR II and L. E2 produced similar DC to K and higher than E1. No significant differences were found on the E' and tan d of E1, E2, and TR II. From the last run, L showed similar E' to E1, E2, and K and higher than NT and TR II. The highest Tg was produced by L. K produced lower Tg than TR II and higher than E1, E2, and NT. All reline materials presented suitable exothermic behavior to clinical use. Overall, the materials formulated with difunctional monomers (E1, E2, and TR II) presented similar properties to the denture resin. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 1669-1676, 2011