In vitro stability of biphasic calcium phosphate ceramics

Area of Science:

• Biomaterials Science
• Materials Science
• Ceramics Engineering

Background:

• Biphasic calcium phosphates (BCP) are widely used in bone regeneration due to their osteoconductivity.
• Understanding the in vitro stability of BCP is crucial for predicting their in vivo performance and degradation.
• BCP ceramics are composed of hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP) in varying ratios.

Purpose of the Study:

• To investigate the in vitro stability of BCP ceramics with different molar ratios.
• To compare the stability of BCP with pure HA and pure β-TCP in aqueous environments.
• To analyze the phase transformation and surface changes of these ceramics upon immersion.

Main Methods:

• Granules of BCP (two molar ratios), pure HA, and pure β-TCP were immersed in deionized distilled water and physiological solutions.
• X-ray diffraction (XRD) was used to analyze phase composition before and after immersion.
• Scanning electron microscopy (SEM) was employed to examine surface morphology changes.

Main Results:

• Pure β-TCP and the β-TCP component within BCP gradually converted to apatite.
• Needle-like apatite crystals were observed on the surfaces of BCP and β-TCP samples.
• Pure HA exhibited no significant phase or morphological changes, indicating high stability.

Conclusions:

• The β-TCP phase in BCP is susceptible to hydrolytic degradation and transformation into apatite in aqueous environments.
• BCP ceramics demonstrate a degree of in vitro stability, with the HA phase remaining largely unchanged.
• The observed apatite formation on β-TCP and BCP surfaces suggests potential for further integration in biological settings.