Properties of novel PMMA‐co‐EHA bone cements filled with hydroxyapatite

Abstract

To design bone cements with predictable intraoperative and postoperative behavior, researchers must understand how cement formulations affect the polymerization reaction and specially the properties of the end product. In this study, a bioactive filler (commercial hydroxyapatite, HA) was incorporated into poly(methyl methacrylate)-co-ethyl hexyl acrylate (PMMA-co-EHA) matrices to prepare new bone cement formulations. The new PMMA-co-EHA/HA composites were obtained by varying the relative contents of the monomers, MMA, and EHA. The resulting composites were evaluated in terms of the curing parameters, water uptake and weight loss in phosphate buffer solution and mechanical properties. The results obtained showed that incorporation of 25% HA particles induced major changes in the final properties of the bone cements comparing with the unfilled parent matrices. In particular, the peak temperature decreased and the setting time and the bending elastic modulus increased in all formulations containing HA particles. Composites with low EHA content exhibited a decrease in strength after HA incorporation, which was attributed to the poor interfacial adhesion between the components of the composites. Additionally, the immersion results showed that the amount of 25% HA (regarding the total mass) in the composites was not enough to induce in vitro bioactive properties in the materials. POLYM. COMPOS., 35:759-767, 2014.

Effect of hydroxyapatite filler concentration on mechanical properties of poly (methyl methacrylate) denture base

“…This can be attributed to the increase of porosity content with the presence of the agglomeration at higher filler content [30]. Due to the increase in porosity content, the incorporation of synthetic bioactive particles, such as the HA ceramic powder into PMMA matrix is limited to concentrations up to 15% of HA [31,32]. Table 2 shows the effect of HA loading on the tensile properties of PMMA/HA composites.…”

Bioactive, Ion‐Releasing PMMA Bone Cement Filled with Functional Graphenic Materials

“…[1,2] Improving the interface between bone cement and native tissue is an area of acute clinical interest. Currently, in the operating room, bone cement is made by mixing a solid filler component, containing polymer beads and a radical initiator, with viable material either, as poor interfacial interactions between cement and mineral typically also result in a significant reduction of mechanical strength [12] -although promising recent reports suggest that improving the interfacial interactions between nonpolymeric filler materials and PMMA can dramatically improve the mechanical performance of the resulting cement. [13,14] As alternatives to mineral fillers, graphenic materials such as graphene oxide (GO) and its functionalized derivatives have been investigated as osteoconductive additives for mechanically tough PMMA bone cement, because of their potential to improve conventional bone cements in unique ways.…”

“…In particular, these cements are more brittle than PMMA and therefore are inappropriate for anchoring load‐bearing prostheses like hip and knee replacements. [ 8,9,11 ] Introduction of bioactive mineral additives to conventional PMMA cement has not yet yielded a clinically viable material either, as poor interfacial interactions between cement and mineral typically also result in a significant reduction of mechanical strength [ 12 ] —although promising recent reports suggest that improving the interfacial interactions between nonpolymeric filler materials and PMMA can dramatically improve the mechanical performance of the resulting cement. [ 13,14 ]…”

Development of a phase change microcapsule to reduce the setting temperature of PMMA bone cement

“…Whereas, the maximum temperature of these modified cements is generally maintained above 50°C, the temperature is still too high for the muscle tissue 12, 13 . Another strategy is to reduce the heat release of polymerization by modification of the MMA monomer through co-crosslinking with N-methyl-pyrrolidone 14 , ethyl hexyl acrylate 15 , glycidyl methacrylate 16 , and acrylic acid 17 . However, the improvement resulting from such a strategy is modest and the introduction of other monomers may cause toxicity to the body.…”