title: Carvable calcium phosphate bone substitute material.
abstract: This study investigated the use of partially set hydroxyapatite forming calcium phosphate cement as a carvable and mechanically stable bone substitute material. Hydroxyapatite-forming cements were made of either mechanically activated alpha-tricalcium phosphate or a mixture of tetracalcium phosphate and dicalcium phosphate anhydrous and setting was arrested up to 4 h post setting. The study showed that these partially set rigid samples of defined geometry could be carved into a desired shape when the degree of reaction was 30-40% and the relative porosity between 40 and 50%; samples are then expected to set completely after implantation in the presence of water or serum, having the same compressive strength as a continuously set calcium phosphate cement (up to 36 MPa). The development of compressive strength, phase composition, and crystallinity when varying production parameters of these partially "preset" bone substitute materials are presented for both cement systems.
authors.affiliation: Biomaterials Unit, School of Dentistry, University of Birmingham, Birmingham B4 6NN, UK. m.p.hofmann@bham.ac.uk
authors.forename: M P
authors.initials: MP
authors.lastname: Hofmann
authors.forename: U
authors.initials: U
authors.lastname: Gbureck
authors.forename: C O
authors.initials: CO
authors.lastname: Duncan
authors.forename: M S
authors.initials: MS
authors.lastname: Dover
authors.forename: J E
authors.initials: JE
authors.lastname: Barralet
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001843:Bone Cements / Q000737:chemistry*; D018786:Bone Substitutes / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D019245:Compressive Strength; D003461:Crystallography; D006801:Humans; D006882:Hydroxyapatites / Q000737:chemistry; D008422:Materials Testing; D019736:Prostheses and Implants; D019651:Plastic Surgery Procedures; D013499:Surface Properties; D013718:Tensile Strength; D014867:Water / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D001843:Bone Cements; D018786:Bone Substitutes; D002130:Calcium Phosphates; D006882:Hydroxyapatites; D014867:Water; C020243:calcium phosphate