In Vivo Evaluation of a Novel Fe2O3-Containing Glass-Ionomer Cement

Introduction: Glass ionomer cements (GIC's) are composed of a basic fluoro-alumnio-silicate glass and an acid polymer. The presence of aluminium in these materials has hindered their use as medical grade bone cements because the release of Al³⁺ from the cement has been associated with poor bone mineralisation and neurotoxicity [1]. Hurrell-Gillingham et al [2,3] have reported the fabrication of a GIC using an Fe₂O₃–based glass, however there have been no studies of bone tissue response published. Objectives: The aim of this study was to evaluate the in vivo biocompatibility of novel Fe₂O₃–based GIC's. Methods: Three GICs were evaluated. 2 Fe₂O₃–based GIC's which have previously shown good handling properties [4] and SerenoCem® a commercial Al₂O₃–based GIC. In vivo biocompatibility was evaluated in a healing defect model in a rat femur after 6 week implantation. Polished ground sections were produced and examined using back scattered scanning electron microscopy. Results: SerenoCem® showed good osteoconductivity. However, the Fe₂O₃–based GIC's showed poor osteoconduction and a large region (possibly fibrous tissue encapsulation) was evident between the implant and the bone, within which particles of cement were observed. Conclusions: The Fe₂O₃–based GIC's did not exhibit good osteoconduction and this is believed to be due to the dissolution of the cement.

References: [1] Brook IM et al. (1998) Biomaterials 19, 565-571 [2] Hurrell-Gillingham et al, (2005), Key Eng. Mat. 284-286, 799-802, [3] Hurrell-Gillingham et al, (2006), J. Dent, 34 533-538, [4] Hurrell-Gillingham et al, IADR/PEF Dublin 2006 #0043.

The authors are grateful to the EPSRC and Medical Devices Faraday Partnership (now Health Technologies KTN) for sponsoring this research (EPSRC grant GR/S78254/01). We also acknowledge Corinthian Surgical for materials.