Thiol-ene oligomers as dental restorative materials

Abstract

The aim of this work was to prereact thiol-ene monomers to create reactive thiol or vinyl (ene)-functionalized oligomers, and to investigate the use of these materials as novel dental restorative material. Investigation has focused on the application of oligomeric thiol-ene materials as dental restorative resins with lower polymerization shrinkage and polymerization stress as compared to monomeric thiol-ene systems and particularly with respect to current dimethacrylate-based systems. Reactive thiol-functionalized oligomers were created via photopolymerization using triallyl-1,3,5-triazine-2,4,6-trione (TATATO), trimethylolpropane tris(3-mercaptopropionate) (trithiol) and pentaerythritol tetramercaptopropionate (tetrathiol). Kinetic and mechanical investigation of Bis-GMA/TEGDMA, and oligomeric and monomeric thiol-ene systems were conducted. More specifically, polymerization shrinkage and stress, polymerization kinetics, glass transition temperature, flexural strength and flexural modulus were evaluated. Upon evaluation, the polymerization stress of oligomeric thiol-ene systems was dramatically reduced by as much as 33% when compared with the stress exhibited by monomeric thiol-ene systems and as much as a 92% reduction in stress relative to the current dimethacrylate-based dental restorative materials. Furthermore, the flexural strength and modulus of the monomeric and oligomeric thiol-ene resins were not significantly different. Oligomeric thiol-ene systems offer potential as alternative dental restorative resins due to the significant reduction in polymerization shrinkage and stress while retaining the mechanical properties of monomer-based thiol-ene resins.