Contact angle and surface free energy of experimental resin-based dental restorative materials after chewing simulation

ObjectiveTo investigate contact angle and surface free energy of experimental dental resin composites containing novel delivery systems of polymeric hollow beads and low-surface tension agents after chewing simulation test.MethodsA delivery system of novel polymeric hollow beads differently loaded with two low-surface tension agents was used in different amounts to modify commonly formulated experimental dental resin composites. The non-modified resin was used as standard. Surface roughness Ra, contact angle Θ, total surface free energy γS, its apolar γSLW, polar γSAB, Lewis acid γS+ and base γS− terms were determined and the results prior to and after chewing simulation test were compared. Significance was p < 0.05.ResultsAfter chewing simulation Ra increased, Θ decreased, Ra increased for two test materials and γS decreased or remained constant for the standard or the test materials after chewing simulation. Ra of one test material was higher than of the standard, Θ and γS of the test materials remained lower than of the standard and, indicating their highly hydrophobic character (Θ ≈ 60–75°, γS ≈ 30 mJ m−2). γSLW, and γS− of the test materials were lower than of the standard. Some of the test materials had lower γSAB and γS+ than of the standard.SignificanceDelivery systems based on novel polymeric hollow beads highly loaded with low-surface tension agents were found to significantly increase contact angle and thus to reduce surface free energy of experimental dental resin composites prior to and after chewing simulation test.