IADR Abstract Archives
Porous Carbonate Apatite Bone Substitute Made from Spherical CaO Microspheres
Objectives: Carbonate apatite (CO3Ap) dense granules bone substitute demonstrated high osteoconductivity and replaced to new bone. Introduction of three-dimensional porous structure to CO3Ap is thought to accelerate replacement to new bone. Objective of this study is to fabricate three-dimensional porous CO3Ap, and evaluate its usefulness histologically using rabbits.
Methods: CaO microspheres was fabricated by heating Ca(OH)2 microspheres made by spray dry method. Mechanical strength in terms of diametral tensile strength (DTS) was measured using universal testing machine. Porosity was calculated using weight and volume of the sample. Composition of the sample was evaluated using XRD, FT-IR and elemental analysis. Histological evaluation (H&E) was performed 4 weeks after reconstruction of the rabbit femur bone defect with the CO3Ap.
Results: When CaO microspheres packed in splitting mold was exposed to water, CaO was hydrated and expanded to be interconnected porous Ca(OH)2. Exposure of porous Ca(OH)2 to CO2 resulted in the transformation form Ca(OH)2 to three-dimension interconnected porous CaCO3. When the interconnected porous CaCO3 was immersed in 1 mol/L Na2HPO4 solution, composition transformed to CO3Ap maintaining the interconnected porous structure. DTS values of CaCO3 and CO3Ap blocks were the same and 0.8MPa ± 0.3 MPa. Porosities of CaCO3 and CO3Ap blocks were 67.7 ± 1.9 % and 60.3 ± 0.3%, respectively.
When bone defect of rabbit tibia was reconstructed with the 3D porous CO3Ap, most of the CO3Ap block was replaced to bone as early as 4 weeks after surgery as shown in a Figure. This replacement is much quicker when compared to dense CO3Ap. We concluded, therefore, that 3D interconnected porous CO3Ap block is useful for the quicker replacement to bone.
Conclusions: 3D porous CO3Ap has good potential value to be an ideal artificial bone substitutes.
Methods: CaO microspheres was fabricated by heating Ca(OH)2 microspheres made by spray dry method. Mechanical strength in terms of diametral tensile strength (DTS) was measured using universal testing machine. Porosity was calculated using weight and volume of the sample. Composition of the sample was evaluated using XRD, FT-IR and elemental analysis. Histological evaluation (H&E) was performed 4 weeks after reconstruction of the rabbit femur bone defect with the CO3Ap.
Results: When CaO microspheres packed in splitting mold was exposed to water, CaO was hydrated and expanded to be interconnected porous Ca(OH)2. Exposure of porous Ca(OH)2 to CO2 resulted in the transformation form Ca(OH)2 to three-dimension interconnected porous CaCO3. When the interconnected porous CaCO3 was immersed in 1 mol/L Na2HPO4 solution, composition transformed to CO3Ap maintaining the interconnected porous structure. DTS values of CaCO3 and CO3Ap blocks were the same and 0.8MPa ± 0.3 MPa. Porosities of CaCO3 and CO3Ap blocks were 67.7 ± 1.9 % and 60.3 ± 0.3%, respectively.
When bone defect of rabbit tibia was reconstructed with the 3D porous CO3Ap, most of the CO3Ap block was replaced to bone as early as 4 weeks after surgery as shown in a Figure. This replacement is much quicker when compared to dense CO3Ap. We concluded, therefore, that 3D interconnected porous CO3Ap block is useful for the quicker replacement to bone.
Conclusions: 3D porous CO3Ap has good potential value to be an ideal artificial bone substitutes.
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