Effect of Liquid/Powder Ratio on the Setting, Handling and Mechanical Properties of Collagen–Apatitic Cements
Due to their insufficient mechanical stability and brittle nature, calcium phosphate cements (CPCs) have not been used for the treatment of vertebral fractures. Mechanical stability of human bone is provided by a complex interaction of type I collagen fibres and hydroxyapatite crystals. In the present study, fibre reinforcement of an apatitic calcium phosphate prepared at different liquid/powder ratio (LPR) was investigated. Different lengths of type I collagen fibres sourced from bovine Achilles tendon were used. Compressive strength and fracture behaviour were examined. Fibre addition of up to 5 wt.% had a significant influence on the compressive properties of the CPC. The mechanism of fibre reinforcement appeared to be crack bridging. Setting time and injectability of the CPC with fibre reinforcement was also investigated and decreased with fibre volume fraction. Increasing the LPR, improved the injectability and delayed the setting reaction. However, the compressive properties of the hardened cement were reduced as a consequence.
Eyup Sabri Kayali, Gultekin Goller and Ipek Akin
N.J. Dunne et al., "Effect of Liquid/Powder Ratio on the Setting, Handling and Mechanical Properties of Collagen–Apatitic Cements", Key Engineering Materials, Vols. 493-494, pp. 415-421, 2012