Heterocyclic methacrylates for clinical applications. I. Mechanical properties

Area of Science:

• Polymer Science and Engineering
• Materials Science
• Biomaterials

Background:

• Low polymerization shrinkage is crucial for dental restorative materials to minimize stress and improve longevity.
• Methacrylate-based polymers are widely used in dentistry, but their shrinkage during polymerization can be a limitation.
• Heterocyclic and cyclic methacrylates offer potential for modifying polymer properties, including shrinkage.

Purpose of the Study:

• To investigate the mechanical properties of novel heterocyclic and cyclic methacrylates for low polymerization shrinkage applications.
• To evaluate their suitability as components in dental restorative materials.
• To assess the performance of both homopolymers and polymer/monomer systems.

Main Methods:

• Synthesis and characterization of homopolymers of various heterocyclic methacrylates.
• Preparation and mechanical testing of room temperature polymerizing systems using poly(ethyl methacrylate) powder and heterocyclic methacrylate monomers.
• Evaluation of isobornyl methacrylate as a cyclic methacrylate control, assessing its polymerizability and compatibility.

Main Results:

• Homopolymers of heterocyclic methacrylates exhibited Young's moduli between 1.38-2.19 GN/m², generally lower than poly(methyl methacrylate).
• Isobornyl methacrylate produced a brittle polymer and was incompatible with poly(ethyl methacrylate) for dough formation.
• Poly(ethyl methacrylate)/monomer systems demonstrated predictable mechanical properties based on homopolymer moduli and showed generally ductile behavior.

Conclusions:

• Certain heterocyclic methacrylates form ductile polymers with mechanical properties suitable for clinical applications.
• The mechanical properties of poly(ethyl methacrylate)/monomer systems can be theoretically predicted.
• Isobornyl methacrylate is not suitable for these low shrinkage applications due to brittleness and incompatibility.