title: Morphological and mechanical characterization of composite bone cement containing polymethylmethacrylate matrix functionalized with trimethoxysilyl and bioactive glass.
abstract: Medical polymers of biostable nature (e.g. polymethylmetacrylate, PMMA) are widely used in various clinical applications. In this study, novel PMMA-based composite bone cement was prepared. Bioactive glass (BAG) particulate filler (30wt%) was added to enhance potentially the integration of bone to the cement. The polymer matrix was functionalized with trimethoxysilyl to achieve an interfacial bond between the matrix and the fillers of BAG. The amount of trimethoxysilyl in the monomer system varied from 0 to 75wt%. The effects of dry and wet (simulated body fluid, SBF at +37°C for 5 weeks) conditions were investigated. In total, 20 groups of specimens were prepared. The specimens were subjected to a destructive mechanical test in compression. Scanning electron microscopy (SEM) and micro-computed tomography (micro-CT) were used to study the surface and the three-dimensional morphology of the specimens. The results of the study indicated that the addition of trimethoxysilyl groups led to the formation of a hybrid polymer matrix which, in lower amounts (<10wt% of total weight), did not significantly affect the compression properties. However, when the specimens stored in dry and wet conditions were compared, the water sorption increased the compression strength (~5-10MPa per test group). At the same time, the water sorption also caused an evident porous structure formation for the specimens containing BAG and siloxane formation in the hybrid polymer matrix.
authors.affiliation: Institute of Dentistry, Department of Biomaterials Science and Turku Clinical Biomaterials Centre (TCBC) and BioCity Turku Biomaterials Research Program, Itäinen Pitkäkatu 4 B, 20520 Turku, Finland; Nordic Institute of Dental Materials-NIOM, University of Oslo, Oslo, Norway. Electronic address: mervi.puska@utu.fi.
authors.forename: Mervi
authors.initials: M
authors.lastname: Puska
authors.affiliation: Institute of Dentistry, Department of Biomaterials Science and Turku Clinical Biomaterials Centre (TCBC) and BioCity Turku Biomaterials Research Program, Itäinen Pitkäkatu 4 B, 20520 Turku, Finland.
authors.forename: Niko
authors.initials: N
authors.lastname: Moritz
authors.affiliation: Institute of Dentistry, Department of Biomaterials Science and Turku Clinical Biomaterials Centre (TCBC) and BioCity Turku Biomaterials Research Program, Itäinen Pitkäkatu 4 B, 20520 Turku, Finland.
authors.forename: Allan J
authors.initials: AJ
authors.lastname: Aho
authors.affiliation: Institute of Dentistry, Department of Biomaterials Science and Turku Clinical Biomaterials Centre (TCBC) and BioCity Turku Biomaterials Research Program, Itäinen Pitkäkatu 4 B, 20520 Turku, Finland; Welfare Division, Turku, Finland.
authors.forename: Pekka K
authors.initials: PK
authors.lastname: Vallittu
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D001843:Bone Cements; D005898:Glass; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D014297:Trimethylsilyl Compounds / Q000737:chemistry*; D055114:X-Ray Microtomography
chemical_list: D001672:Biocompatible Materials; D001843:Bone Cements; D014297:Trimethylsilyl Compounds; D019904:Polymethyl Methacrylate
keywords: Acrylic bone cement; Bioactive composite; Hybrid matrix polymer; Micro-CT; Porosity