Studies in polymer alloys for applications in prosthetics

Abstract

This study relates to the preparation of polymer composites with properties of interest in dental and medical fields. These applications concern, bone cements which are used in total hip replacement operations, tooth filler composites, radiopaque composites and high impact materials used in the manufacturing of denture bases. A bone cement comprising apatite copolymer was prepared with properties which allow direct bonding to the poly(methyl methacrylate)(PMMA) polymer matrix and promotes bone ingrowth into the cement. Novel radiopaque materials were prepared and analysed by x-ray which revealed values greater or similar to those found with dentine or enamel. These radio-adjustable materials have the potential to be useful filling materials and to impart radiopacity to PMMA which is used in the manufacture of acrylic teeth and denture bases. In the case of high impact materials, preparation was carried out by suspension polymerisation and the impact strengths and modulus calculated. A formulation is shown with improved characteristics than those found for commercially available materials. The aim throughout has been the ability to transfer reaction conditions from bench to plant scale. Combinations of poly(butyl methacrylate) (PBMA), poly(ethyl methacrylate) (PEMA) and PMMA were re-examined for compatibility using DSC and NMR (solid state). It was found that limited compatibility exists in the solid state. In solution, agreeing with previous studies, incompatibility was shown.