Bone bonding ability and handling properties of a titania–polymethylmethacrylate (PMMA) composite bioactive bone cement modified with a unique PMMA powder

One of the challenges of using bioactive bone cements is adjusting their handling properties for clinical application. To resolve the poorer handling properties of bioactive bone cements we developed a novel bioactive bone cement containing a unique polymethylmethacrylate (PMMA) powder, termed SPD-PMMA (40 μm in diameter), composed of cohered minute particles of PMMA (0.5 μm). The present study aimed to examine the mechanical and handling properties and the in vivo bone bonding strength of this cement. The titania content of the cement varied from 10 to 30 wt.% (Ts10, Ts20, and Ts30). The mechanical and thermal properties of Ts10 and Ts20 exceeded those of commercially available PMMA cements (PMMAc). The setting properties of Ts20, including a shorter dough time and a working time that was comparable with that of PMMAc, were adequate for clinical application. Hardened cylindrical cement specimens were inserted into rabbit femurs and the interfacial shear strengths were measured by a push-out test at 6, 12, and 26 weeks after the operation. The interfacial shear strength values (in Newtons per square millimeter) of Ts10, Ts20, and Ts30 at 12 weeks and those of Ts20 and Ts30 at 26 weeks were significantly higher than that of PMMAc (P < 0.05). These results show that a bioactive titania–PMMA composite bone cement modified by SPD-PMMA particles possesses adequate mechanical and handling properties, as well as osteoconductivity and in vivo bone bonding ability, and can be used for prosthesis fixation.