Evaluation and comparison of synthesised hydroxyapatite in bone regeneration: As an in vivo study

Objectives: Many patients suffer from non-repaired bone defects and subsequent aesthetic and psychological problems following bone fractures from accidents. The main goal of the study was to compare and evaluate synthetic hydroxyapatite with xenograft and commercial hydroxyapatite for bone repair and reconstruction.

Methods: In this study, synthetic hydroxyapatite was fabricated and verified. Cytotoxicity tests (i.e., induction coupled plasma [ICP], density and porosity analysis, scanning electron microscope [SEM] analysis, and thiazolyl blue tetrazolium blue [MTT] assay) were performed. Synthetic, xenograft, and commercial hydroxyapatite were tested in the animal study. Finally, bone regeneration was assessed using haematoxylin and eosin (H&E) staining.

Results: The Ca/P ratio was measured for xenograft and commercial samples, and values were lower than those for the synthesised hydroxyapatite. The amount of surface porosity in the synthesised sample was greater than in the commercial and xenograft samples. Additionally, the density of the synthesised hydroxyapatite was lower than that of the xenograft and commercial samples. A small amount of ossification from natural bone margins was observed at 4 weeks in the xenograft and commercial hydroxyapatite group. In the synthetic group, immature bone formation was observed at 4 weeks. The rate of ossification and cell infiltration in the xenograft and commercial hydroxyapatite samples was higher at 8 weeks than at 4 weeks, and this rate was lower than in the synthesised hydroxyapatite group. The synthesised hydroxyapatite group exhibited greater ossification than the xenograft and commercial hydroxyapatite, and control groups at 12 weeks.

Conclusion: This study showed that synthesised hydroxyapatite had better effects on bone regeneration and could be used in bone tissue engineering.