The effect of composition and annealing on the properties of aluminum free GPCs: A preliminary evaluation.

Abstract: Glass polyalkenoate cements (GPC) comprising zinc borogermanate glass may have clinical potential as injectable bone cements. However significant improvements in setting characteristics are required, i.e. significant extension of working/setting times into clinical relevant ranges is required without compromising strength. Achieving such features may be possible via reducing the zinc to germanium ratio of such glasses coupled with an annealing process. The reactivity of non-annealed and annealed experimental glasses with Zn:Ge ratios between 1:0.64 and 1:1.11 were compared by measuring GPC working times, setting times, and compressive strengths. The working and setting time results were impressive, and ranged from 2–15 and 5–31min, respectively, influenced by both Zn:Ge ratio and annealing. Interestingly, abrupt and significant changes in handling properties were observed in both non annealed and annealed GPCs as the Zn:Ge ratio passed 1:1. The strongest composition comprised an annealed glass with a 1:0.74 ratio, which demonstrated 30MPa at 1 day increasing to 39 MPa at 30 days. The influence of glass annealing on GPC strength was found to be compositionally dependent. These experimental GPCs demonstrated handling characteristics sufficient for use as injectable bone cements [Copyright &y& Elsevier]