A novel multiphase anodic spark deposition coating for the improvement of orthopedic implant osseointegration: An experimental study in cortical bone of sheep.

The effect of a new three-step anodic spark deposition process, labeled TiSpark, including two consecutive treatments performed first in a P solution and second in Ca solution, followed by an additional alkali etching step, was investigated for the improvement of osseointegration of commercial grade 2 titanium, machined (Ti) or Al2O3 sandblasted (Ti-SA), cylindrical implants (12 mm in length and 4 mm in diameter) in cortical bone of 12 adult sheep. Histomorphometric and microhardness measurements were carried out at each experimental time (4, 8, and 12 weeks) to quantify the bone-to-implant contact around the implants as well as the newly bone hardness and bone maturation index. TiSpark treated surfaces were covered by a thick layer of crystalline anatase TiO2 and by a further Ca/P layer. Bone tissue extends and grows on the surface of the TiSpark treated implants without any fibrous tissue, enhancing the short-term osseointegration properties of implant. Bone mineralization rate was also influenced by the chemical composition of implants and sandblasted materials presented the lowest bone maturation rate at the interface. Data suggests that the TiSpark treatment produces a modification of the Ti surface, which presents good bioactivity and may be suitable for achieving a stable implant osseointegration.