Material behavior of resin composites with and without fibers after extended water storage.

The objective of this study was to determine the long-term water sorption, solubility and hygroscopic expansion of resin composites with and without incorporated short fibers. Three resin composites incorporating fibers were examined: everX Posterior (EVX), NovoPro Universal (NPU) and NovoPro Flow (NPF). Four Particulate filled composites were used as controls: Filtek bulk Fill (FBF), Filtek one bulkfill (FBO), Filtek Supreme XTE (XTE), and Filtek Supreme Flow (XTEF). For sorption and solubility measurements, specimens were immersed in water for140 days, weighed at intervals, then dried for a further 42 days at 37±1°C. Laser micrometer measured diametral expansion. XTEF exhibited the highest sorption. The solubility range was between -1.4 to 4.1 μg/mm; XTEF had the highest solubility, with EVX demonstrating negative solubility. Hygroscopic expansion ranged between 1.4% for hydroxyapatite fiber reinforced composite (NPU) and 2.2% for E-glass fiber reinforced composite (EVX). A nano-fiber containing composite (NPU) had the most favorable outcomes compared to a range of composites.