High-temperature high-pressure polymerized urethane dimethacrylate-mechanical properties and monomer release

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomaterials Engineering

Background:

• Urethane dimethacrylate (UDMA) is a common dental resin monomer.
• Polymerization methods influence the mechanical properties and monomer elution of UDMA-based resins.
• High-temperature, high-pressure (HT/HP) polymerization is an advanced technique with potential benefits.

Purpose of the Study:

• To evaluate the mechanical/physical properties of UDMA polymerized using HT/HP methods.
• To quantify monomer release from HT/HP polymerized UDMA.
• To compare HT/HP polymerized UDMA with other polymerization protocols.

Main Methods:

• Five UDMA resin blocks were produced using different polymerization protocols.
• Flexural strength, hardness, fracture toughness, and density were measured.
• High-performance liquid chromatography (HPLC) was used to determine monomer release.
• Statistical analyses included one-way ANOVA, Scheffé tests, and Weibull statistics.

Main Results:

• HT/HP polymerization significantly increased flexural strength and density.
• No significant differences in hardness or fracture toughness were observed between HT/HP polymerized materials.
• Monomer release was significantly lower in HT/HP polymerized groups.
• Weibull modulus for flexural strength also increased with HT/HP polymerization.

Conclusions:

• HT/HP polymerization enhances UDMA's mechanical properties and significantly reduces monomer release.
• Improved properties suggest a higher degree of conversion and reduced inhomogeneity.
• Further research may explore filler-matrix interactions in HT/HP polymerized composites.