The synthesis of Bis-GMA oligomers and their effects upon the properties of some experimental dental composites

In the present work a mixture of three components: Bis-GMA(n) (n = 0, 1, an d 2), having 83 mol % Bis-GMA(o) monomer-2,2-bis[4-(2-hydroxy-3-methacryloy loxypropoxy)phenyl]-propane- 16 mol % Bis-GMA(1) dimer and 1 mol % Bis-GMA( 2) trimer has been synthesized. The Bis-GMA(0-2) oligomers mixture and othe r dimethacrylate monomers have been used to formulate some experimental den tal composites. The composites were formulated in the liquid-powder system and were chemically cured. The paper studies the influences of the monomers upon the gel time, polymerization shrinkage, compressive strength, tensile strength, and water sorption of the cured experimental composites. We came to the conclusion that the composites originated from the synthesized Bis- GMA(0-2) oligomers mixture have a lower polymerization shrinkage than the c omposites originated from Bis-GMA(0) monomer. The strength properties aid w ater sorption values of the Bis-GMA(0-2)-based composites are in the same r ange as those for the Bis-GMA(0)-based composites.