The reason that silane is not effective in universal adhesive systems is because Bis-GMA and other resins in the same formula inhibit the condensation reaction.110 The condensation reaction occurs between the silanol (-Si-OH-) and ceramic substrate’s –OH group, slowly liberating water molecules to form stable siloxane (-Si-O-Si-) bonds.110 The liberation of water molecules is essential for the condensation reaction to continue, which can be inhibited by the presence of extra resin, which slows water evaporation (Le Chatelier’s principle).
Published on Apr 30th 2014