Preheating Impact on the Degree of Conversion and Water Sorption/Solubility of Selected Single-bottle Adhesive Systems

Abstract

This study evaluated the degree of conversion (DC) and the water sorption/solubility of preheated single-bottle adhesive systems. Five adhesive systems were tested: Adper Easy One and Adper Single Bond 2 (3M ESPE), Excite and Tetric N-Bond (Ivoclar/Vivadent), and XP Bond (Dentsply/Caulk). After storage for two hours at 25°C or 60°C, 50 samples (n=5) were prepared for all adhesive systems and stored dry in lightproof containers at 37°C for 24 hours. Fourier transform infrared/attenuated total reflectance spectroscopy was used to evaluate the DC, and water sorption/solubility was measured by means of mass loss and gain after water storage. The data were analyzed by two-way analysis of variance followed by Tukey's test (p<0.05). Preheated adhesive systems showed statistically significantly higher DC than those kept at 25°C. Except for XP Bond, preheated adhesive systems presented statistically significantly lower water sorption/solubility means. Preheating improved the DC for all tested adhesive systems. Also, it promoted a decrease of water sorption/solubility, except for the XP Bond adhesive system.