In vitro stability of biphasic calcium phosphate ceramics.

Biphasic calcium phosphate ceramics consist of both beta-tricalcium phosphate and hydroxyapatite. This study was performed to examine the in vitro stability of biphasic calcium phosphate ceramics in deionized distilled water and in physiological solutions. Biphasic calcium phosphates of two different molar ratios and pure hydroxyapatite and pure beta-tricalcium phosphate granules were tested. X-ray diffraction data were obtained before and after immersion. Surface morphology was compared using scanning electron microscopy. The pure beta-tricalcium phosphate and the beta-tricalcium phosphate in the biphasic calcium phosphate ceramics gradually converted to apatite. Needle-like apatite crystals were observed on the surface of biphasic calcium phosphate and beta-tricalcium phosphate, but hydroxyapatite showed no change.