title: Comparative study on the resorbability and dissolution behavior of octacalcium phosphate, β-tricalcium phosphate, and hydroxyapatite under physiological conditions.
abstract: The dissolution behaviors of octacalcium phosphate (OCP), β-tricalcium phosphate (β-TCP), and hydroxyapatite (HA) were compared by implanting the materials in rat subcutaneous pouches for 8 weeks using a filter chamber or immersing them in simulated body fluid (SBF) or Tris-HCl buffer for 2 weeks at pH 7.4 and 37(o)C. X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and chemical analysis were conducted on these materials. Degree of supersaturation (DS) in the two solutions immersed with each calcium phosphate material was calculated from their chemical compositions. The results showed that OCP partially converted to apatitic crystals, while β-TCP and HA remained unchanged after the implantation. The DS of the SBF solution remained slightly supersaturated with respect to OCP and β-TCP, but slightly undersaturated in the Tris-HCl buffer. These findings suggest that previously reported OCP and β-TCP biodegradation could be induced through cell-mediated osteoclastic resorption rather than a simple dissolution process.
authors.affiliation: Division of Craniofacial Function Engineering, Tohoku University Graduate School of Dentistry.
authors.forename: Susumu
authors.initials: S
authors.lastname: Sakai
authors.forename: Takahisa
authors.initials: T
authors.lastname: Anada
authors.forename: Kaori
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: Hajime
authors.initials: H
authors.lastname: Yamazaki
authors.forename: Henry C
authors.initials: HC
authors.lastname: Margolis
authors.forename: Osamu
authors.initials: O
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D001031:Apatites; D001826:Body Fluids; D002130:Calcium Phosphates; D017886:Durapatite; D008855:Microscopy, Electron, Scanning; D051381:Rats; D012995:Solubility; D014961:X-Ray Diffraction
chemical_list: D001031:Apatites; D002130:Calcium Phosphates; D017886:Durapatite