Factors affecting the transformation of octacalcium phosphate to apatite in vitro.
A fresh octacalcium phosphate (OCP) precipitate without drying and three kinds of dried OCP powders were soaked for 3 weeks in 11 kinds of physiological solutions consisting of different combinations of Ca2+, Mg2+, K+, Na+, HCO3-, HPO4(2-), F-, albumin, collagen and alkaline phosphatase, in three different pH values and at three different temperatures. X-ray diffraction study showed that most of the OCP had been transformed to apatite with low crystallinity after soaking in the solutions without Mg2+. The IR absorption spectra revealed that CO3 was incorporated in the apatite formed from OCP in the solution without Mg2+, whereas OCP changed little after soaking in the solution containing Mg2+. These results suggest that the presence of Mg2+ in the solution is one of the most effective means of inhibiting the transformation of OCP to apatite by interrupting the precipitation process of apatite.
Ban
S
S
Department of Dental Material Science, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan.
Matsuura
M
M
Arimoto
N
N
Hayashizaki
J
J
Itoh
Y
Y
Hasegawa
J
J
D000704:Analysis of Variance; D001031:Apatites / Q000138:chemical synthesis*; D002130:Calcium Phosphates / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D013055:Spectrophotometry, Infrared; D014961:X-Ray Diffraction
D001031:Apatites; D002130:Calcium Phosphates; C022045:octacalcium phosphate; D008274:Magnesium