Beschreibung
Methyl methacrylate (MMA) is the basic component of bone cements. To use it, a dough is prepared from the liquid and powder by mixing right before application, which is normally done by the operating team. During its working phase the dough is then inserted into the tissue where polymerization is completed. Thus, the final implant polymethyl methacrylate (PMMA) is only created at the implantation site. Besides methyl methacrylate, bone cements sometimes contain other methacrylates, such as butyl methacrylate. To achieve X-ray opacity, radiopacifiers (zirconium dioxide or barium sulfate) are added to the powder. Both the liquid and powder components contain additives (initiator and activator) that launch polymerization and control the set ting when mixed together. Moreover, softener and emulsifiers are some times used. The addition of antibiotics to the powder component in order to prevent or treat infections has become especially important. Commercial bone cements differ in composition and the course of curing. Some are designed for high and others for low viscosity. The way the user handles and applies the cement always crucially influences the quality of the implant. This is why clear and comprehensive information about the cements should be available to show the user how all the relevant factors work It should also be possible together and how they depend on each other.
Inhalt
Inhaltsangabe1 Introduction and Scope.- 2 Test Material and Applied Methods.- 2.1 Material.- 2.2 Applied Test Methods.- 2.2.1 Description of the Cements.- 2.2.2 Determination of the Polymer Composition.- 2.2.3 Determination of the Benzoyl Peroxide Content.- 2.2.3.1 Titration.- 2.2.3.2 High-Performance Liquid Chromatography.- 2.2.4 Determination of the Content of Radiopaque Medium.- 2.2.5 Representation of the Radiopacity.- 2.2.6 Release of Residual Monomer.- 2.2.7 Residual Monomer Content.- 2.2.8 Determination of the Gentamicin Content.- 2.2.9 Determination of the Release of Gentamicin.- 2.2.10 Determination of the Molecular Weight.- 2.2.11 Determination of the Monomer Composition.- 2.2.12 Determination of the Monomer Stability According to ISO 5833.- 2.2.13 Determination of the Bending Strength (Three-Point) According to German Industrial Standard 53435.- 2.2.14 Determination of the Impact Strength According to German Industrial Standard 53435.- 2.2.15 Determination of Bending Strength (Four-Point) According to ISO 5833.- 2.2.16 Determination of Compressive Strength According to ISO 5833.- 2.2.17 Determination of the Bending Modulus According to ISO 5833.- 2.2.18 Determination of Intrusion According to ISO 5833.- 2.2.19 Determination of the Setting Temperature/Time According to ISO 5833.- 2.2.20 Determination of the Doughing Time According to ISO 5833.- 2.2.21 Determination of the Working Properties.- 2.2.22 Determination of the Glass Transition Temperature.- 2.2.23 Determination of Fatigue Strength.- 3 Results and Discussion.- 3.1 PMMAs as Bone Cements.- 3.1.1 Initiator System for Polymerization.- 3.1.2 Polymerization Heat.- 3.1.3 Residual Monomer.- 3.1.4 Handling and Viscosity.- 3.1.4.1 Mixing Phase.- 3.1.4.2 Working Phase.- 3.1.4.3 Hardening Phase.- 3.1.5 Molecular Weight.- 3.1.6 Mechanical Properties.- 3.1.7 Glass Transition Temperature.- 3.2 Descriptions of the Cements.- 3.2.1 Antibiotic-Free (Plain) Cements.- 3.2.1.1 C-ment 1.- 3.2.1.2 C-ment 3.- 3.2.1.3 Cemex Isoplastic (High Viscosity).- 3.2.1.4 Cemex RX (Low Viscosity).- 3.2.1.5 Cerafix LV.- 3.2.1.6 CMW1.- 3.2.1.7 CMW 2.- 3.2.1.8 CMW 3.- 3.2.1.9 Duracem 3.- 3.2.1.10 Durus H.- 3.2.1.11 Endurance.- 3.2.1.12 Osteobond.- 3.2.1.13 Osteopal and Palacos LV (E Flow).- 3.2.1.14 Osteopal HA.- 3.2.1.15 Osteopal VS.- 3.2.1.16 Palacos R.- 3.2.1.17 Palamed.- 3.2.1.18 Palavit HV:.- 3.2.1.19 Palavit LV.- 3.2.1.20 Surgical Simplex P and Surgical Simplex P with Microlok.- 3.2.1.21 Surgical Subiton RO.- 3.2.1.22 Zimmer Dough-Type Radiopaque Cement.- 3.2.2 Comparison of Plain Cements.- 3.2.2.1 Setting Time and Temperature.- 3.2.2.2 Compressive Strength.- 3.2.2.3 Dynstat Bending Strength.- 3.2.2.4 Dynstat Impact Strength.- 3.2.2.5 ISO Bending Strength.- 3.2.2.6 Modulus of Elasticity.- 3.2.3 Antibiotic-Loaded Cements.- 3.2.3.1 Antibiotic Simplex (= AKZ).- 3.2.3.2 Allofix G.- 3.2.3.3 Cemex-Genta HV.- 3.2.3.4 Cemex-Genta LV.- 3.2.3.5 Cerafixgenta.- 3.2.3.6 CMW 1 G.- 3.2.3.7 CMW 2 G.- 3.2.3.8 CMW 3 G.- 3.2.3.9 CMW 2000 Gentamicin.- 3.2.3.10 Copal.- 3.2.3.11 Genta C-ment 1.- 3.2.3.12 Genta C-ment 3.- 3.2.3.13 Osteopal G and Palacos LV + G/E Flow with Gentamicin.- 3.2.3.14 Refobacin-Palacos R and Palacos R with Gentamicin.- 3.2.3.15 Palamed G.- 3.2.3.16 Surgical Subiton G.- 3.2.4 Comparative Tests of Antibiotic-Loaded Cements.- 3.2.4.1 Setting Time and Temperature.- 3.2.4.2 Compressive Strength.- 3.2.4.3 Dynstat Bending Strength.- 3.2.4.4 Dynstat Impact Strength.- 3.2.4.5 ISO Bending Strength.- 3.2.4.6 Modulus of Elasticity.- 3.2.5 Further Comparative Studies.- 3.2.5.1 Working Time.- 3.2.5.2 Molecular Weight.- 3.2.5.3 Long-Term Load-Cycling Tests.- 3.2.5.4 Radiopacity.- 3.2.5.5 Residual Monomer and DmpT in the Polymerized Cement.- 3.2.5.6 Glass Transition Temperature.- 3.2.5.7 Release of Active Ingredients.- 3.2.5.8 Summarizing Evaluation.- References.
