Enhanced osteobonding by negative surface charges of electrically polarized hydroxyapatite

Negative surface charges of electrically polarized hydroxyapatite ceramics have been proven to enhance osteobonding in canine bone tissues. Even in a wide gap of 0.2 mm between hydroxyapatite and bone, the negatively charged hydroxyapatite conducted formation of unidirectionally oriented bone layer into direct contact with the hydroxyapatite surface 7 days after implantation. By day 14, the gap was filled with maturing bones linked to each other while conventional hydroxyapatite required at least 28 days for direct bone-to-bone contact. The electrostatic force was deduced to have affected both the activation of bone formation by myeloid cells and the orientation of the bone domain on negatively charged surfaces.