Comparative study of hydroxyapatite from eggshells and synthetic hydroxyapatite for bone regeneration.
OBJECTIVE
The objective of this study was to evaluate the physical properties of synthetic hydroxyapatite (sHA) and hydroxyapatite from eggshells (eHA) by Fourier-transform infrared (FT-IR) and x-ray diffraction (XRD) and to compare the regenerative ability of the bone using sHA and eHA in a rabbit calvarial defect model.


METHODS
FT-IR and XRD were used to compare the physical properties of sHA and eHA. sHA was purchased from Sigma, and eHA was kindly donated from the Hungarian academy of science. 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 after the operation.


RESULTS
The peak broadening of the XRD experiments were in agreement with scanning electron microscope observation; the sHA had a smaller granule size than the eHA. The eHA had impurities phases of CaO (International Center for Diffraction Data (ICDD) 075-0264) and Ca(OH)(2) (ICDD 072-0156). 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. The difference was not statistically significant (P > .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. When comparing the sHA group to the control group, the difference was not statistically significant (P > .05). However, the eHA group was significantly different from the control group (P = .038). When comparing the eHA group to the sHA group, the difference was not statistically significant (P > .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 after operation.
Department of Oral and Maxillofacial Surgery, College of Dentistry, Gangneung-Wonju National University, Gangneung, Republic of Korea.
Sang-Woon
SW
Lee
Seong-Gon
SG
Kim
Csaba
C
Balázsi
Weon-Sik
WS
Chae
Hee-Ok
HO
Lee
D000818:Animals; D001861:Bone Regeneration / Q000187:drug effects*; D018786:Bone Substitutes / Q000138:chemical synthesis / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D017886:Durapatite / Q000138:chemical synthesis / Q000494:pharmacology*; D004528:Egg Shell / Q000737:chemistry; D011817:Rabbits; D012886:Skull / Q000293:injuries*; D017550:Spectroscopy, Fourier Transform Infrared
D018786:Bone Substitutes; D017886:Durapatite