title: Evaluation of apatite ceramics containing alpha-tricalcium phosphate by immersion in simulated body fluid.
abstract: The purpose of this study was to estimate the availability of alpha-tricalcium phosphate (alpha-TCP) on/in hydroxyapatite (HAP) ceramics for bioactivity as bone-substitute materials by immersion in a simulated body fluid (SBF; Hanks' solution) containing ion concentrations similar to those in human blood plasma. Two alpha-TCP-surface-modified HAP and alpha-TCP-HAP composite materials were prepared by orthophosphoric acid treatment of sintered HAP and controlling the crystal phases of calcium phosphate cement, respectively. After immersion in SBF, the sintered HAP modified on the surface in an approximately 0.2 microm alpha-TCP layer was more effective for the precipitation of carbonated apatites than an approximately 2 microm alpha-TCP layer and HAP-only layer. In the calcium phosphate cements consisting of HAP and alpha-TCP phases, after immersion for 1 week, the specimens precipitated large amounts of apatites having alpha-TCP contents of approximately 25% and 50% in the cement. The results of immersion tests imply the possibility that the alpha-TCP on/in HAP ceramics may be a bioactive agent for bone-substituting HAP materials.
authors.affiliation: Department of Dental Engineering, The University of Tokushima, School of Dentistry, Kuramoto, Tokushima, Japan.
authors.forename: Luciana M
authors.initials: LM
authors.lastname: Hirakata
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kon
authors.forename: Kenzo
authors.initials: K
authors.lastname: Asaoka
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry; D001826:Body Fluids / Q000737:chemistry*; D001843:Bone Cements / Q000737:chemistry; D018786:Bone Substitutes / Q000138:chemical synthesis / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis / Q000737:chemistry; D017886:Durapatite / Q000737:chemistry*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007101:Immersion; D008422:Materials Testing / Q000379:methods*; D008968:Molecular Conformation; D013499:Surface Properties
chemical_list: D001843:Bone Cements; D018786:Bone Substitutes; D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C485838:calcium phosphate, monobasic, anhydrous; D017886:Durapatite; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous