Residual monomer in acrylic polymers.

Area of Science:

• Polymer Chemistry
• Dental Materials Science
• Biomaterials

Background:

• Acrylates, distinct from methacrylates, are present in some dental resins.
• Acrylates are associated with adverse skin reactions, necessitating their characterization.
• Bone cements are widely used in orthopedic and dental procedures, with potential for monomer leaching.

Purpose of the Study:

• To identify and quantify acrylate monomers in proprietary dental resins.
• To determine the release kinetics of extractable free monomers from dental bone cements.
• To investigate factors influencing monomer diffusion and release from polymerized and unpolymerized materials.

Main Methods:

• Gas chromatography was used to identify and quantify acrylate monomers in dental resins.
• Extraction experiments were performed on both unpolymerized and polymerized bone cement materials.
• Monomer concentrations were measured over time to establish release kinetics.

Main Results:

• Proprietary dental resins were found to contain methyl acrylate and ethyl acrylate.
• The extraction of n-butyl methacrylate from experimental bone cement was significantly lower than methyl methacrylate from proprietary bone cement.
• Monomer release kinetics deviated from simple diffusion theory, indicating continued polymerization and concentration-dependent diffusion.

Conclusions:

• The presence of specific acrylates in dental resins requires careful consideration due to potential adverse reactions.
• Bone cement composition significantly impacts the rate and extent of free monomer release.
• Complex polymerization and diffusion dynamics govern monomer leaching from bone cements, affecting material safety and performance.