The monomeric components of resin composites in dental restorative materials are susceptible to hydrolysis in the oral cavity. The main objective of this study was to assess the bio-stability of fluorinated urethane dimethacrylates and determine the nature of fluoro-chemistry interactions with protein and bacterial adhesion (both sources of hydrolytic activity) onto cured resin. Degradation studies were performed in the presence of either albumin (in a mildly alkaline pH) or cholesterol esterase (CE). The surface chemistry of the polymers was assessed by water contact angle measurements, pre- and post- incubation with albumin. Adhesion of Streptococcus mutans to cured resin was investigated. The fluorinated monomers were more stable against degradation when compared to the commercial monomer bisphenol A-diglycidyl methacrylate (BisGMA). While fluorinated monomers showed hydrolytic stability with respect to CE, all fluorinated monomers underwent some degree of degradation with albumin. The fluoro-chemistry did not reduce protein and/or bacterial adhesion onto the surface, however post incubation with albumin, the fluorinated surfaces still presented hydrophobic character as determined by the high contact angle values ranging from 79° to 86°. These monomers could potentially be used to increase the hydrophobicity of polymeric composites and provide a means to moderate esterolytic degradation associated with the monomeric component of the polymers within the oral cavity.
Keywords: albumin; degradation; fluorinated monomers; methacrylates; proteins; resin composites; surfaces; urethane.