Electrostatic surface charge acceleration of bone ingrowth of porous hydroxyapatite/β-tricalcium phosphate ceramics

Bone ingrowth enhancement by the surface induced charges of the electrically polarized hydroxyapatite (HA)/β‐tricalcium phosphate (β‐TCP) ceramics was histologically investigated to clarify the early stage events of ossification. The HA/β‐TCP specimens with a relatively low porosity of 45% for bone ingrowth were polarized in a dc electric field at 400°C for 1 h. The large preserved charges of 8 μC cm−2 significantly promoted the bone ingrowth process of the porous ceramics implanted in femoral diaphyses of New Zealand white rabbits. The bone formation in the pores of the polarized HA/β‐TCP specimens was observed within 1 week after surgery. The bone occupancy of the polarized HA/β‐TCP pores reached more than 90% at as early as 2 weeks and significantly higher than that of the nonpolarized. The electrical polarization was proved to be effective for bone penetration improvement of low porosity ceramics. The electrically polarized HA/β‐TCP bone grafts with a lower porosity and a higher mechanical strength combined high osteoconductivity generated by the induced surface charges. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010