title: Gamma-radiation-induced changes in structure and properties of tetracalcium phosphate and its derived calcium phosphate cement.
abstract: The purpose of the present study was to investigate the gamma-radiation effect on the structure and properties of the single-phase tetracalcium phosphate (TTCP) powder and its derived calcium phosphate cement (CPC). Experimental results show that low-dosed (0-30 kGy) CPC has a setting time of 10-12 min, while high-dosed (40-120 kGy) CPC has a setting time of 8-10 min. The low dose gamma-radiation does not significantly change porosity volume fraction or compressive strength of the CPC. The pH values of all CPC samples fell in a relatively narrow band, with a band width of 8.5-9.1 (in terms of pH value). With a dose of 10 or 20 kGy gamma-radiation, the TTCP-apatite conversion ratio does not change much. With 30 kGy the conversion ratio significantly increases and reaches a maximum value. With further increases in dose, the conversion ratio quickly declines. With increasing gamma-ray dose, the CPC morphology becomes more porous/loose and apatite particles become larger in size. When exposed to a high dose (120 kGy) of gamma-radiation, TTCP structure is radiation-damaged, and gamma-ray-induced formation of apatite is confirmed by transmission electron microscopic/selected-area diffraction/lattice imaging analyses.
authors.affiliation: Department of Materials Science and Engineering, National Cheng-Kung University, 70101 Tainan, Taiwan, Republic of China.
authors.forename: Chih-Hung
authors.initials: CH
authors.lastname: Tsai
authors.forename: Jiin-Huey Chern
authors.initials: JH
authors.lastname: Lin
authors.forename: Chien-Ping
authors.initials: CP
authors.lastname: Ju
mesh_terms: D001843:Bone Cements / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D008422:Materials Testing; D016062:Porosity / Q000528:radiation effects; D013242:Sterilization / Q000379:methods; D013997:Time Factors
chemical_list: D001843:Bone Cements; D002130:Calcium Phosphates; C485830:tetracalcium phosphate