A novel functional gradient hydroxyapatite coating for zirconia-based implants

Abstract

Abstract: The bioactivity of zirconia in osseous-implant applications has been debated widely. Acid etching, grit blasting, etc., were employed to improve the microroughness and osseointegration. Coating of calcium phosphate minerals, which are established for metals like titanium is not compatible with zirconia and suffers delamination. Here ceramic dough processing-based composite slurry having HAp and zirconia was explored to form a thin (~10 μm) gradient coating on a zirconia dental screw implant. The coating has a homogeneous distribution of secondary phase without affecting the fine machined features like threads. Further, the matrix is porous with increased roughness, but a minimal compromise on strength. During the scratch test, the coating survived a normal load >70 N using a diamond indenter without any significant spalling or delamination. Given the simplicity and versatility, this approach is compatible and a promising solution for currently available bio-inert zirconia implants.