Evaluation of a thiol-ene-methacrylate system as dental restorative material with low shrinkage stress and high monomer conversion

Methacrylate based restorative dental materials suffers from shrinkage stress and strain during their photochemical polymerization [1]. Since dental restorative materials are bondedto the tooth cavity walls, shrinkage occurring under the confined geometry results in shrinkage stress. The gap formation betweencomposite and tooth structure will provide a place for bacteria penetration and secondary caries [2-4]. The thiol-ene systemsprovide lower shrinkage stress and strain. In this system gelation occurs later comparing to the conventional methacrylate systemswhich results in stress relaxation prior to vitrification of the system. In this study a urethane-based allyl ether monomer (UAEM) was incorporated into a methacrylate resin system and its effects on the shrinkage stress behavior during photpolymerization reaction was studied