Aim: The objective of this study was to evaluate the physical properties of synthetic hydroxyapatite (sHA) and hydroxyapatite from eggshells (eHA) and to compare the regenerative ability of the bone using sHA and eHA.

Materials and methods: FT-IR and XRD was used to compare the physical properties of sHA and eHA. Sixteen New Zealand white rabbits were used for the animal study. After the formation of a bilateral parietal bony defect (diameter: 8.0 mm), either sHA or eHA was grafted into the defect. The defect in the control was left unfilled. Bone regeneration was evaluated by histomorphometry at 4 and 8 weeks postoperatively.

Results: The peak broadening of the XRD experiments were in agreement with the SEM observation; the sHA had a smaller granule size than the eHA. Total new bone was 17.11 ± 10.24% in the control group, 28.81 ± 12.63% in sHA group, and 25.68 ± 10.89% in eHA group at 4 weeks after the operation ( p > 0.05). Total new bone at 8 weeks after the operation was 27.50 ± 10.89% in the control group, 38.62 ± 17.42% in sHA group, and 41.99 ± 8.44% in the eHA group. The eHA group was significantly different from the control group ( p = 0.038). When comparing the eHA group to the sHA group, the difference was not statistically significant ( p > 0.05).

Conclusions: Both types of HA showed higher bone formation than the unfilled control. However, eHA had significantly higher bone formation than the unfilled control at 8 weeks postoperatively.

Conflict of interest: None declared.