Relationship between osteogenic characteristics of bone marrow cells and calcium phosphate surface relief and solubility.

The capacity of mouse bone marrow cells to adhere to calcium phosphate surfaces and form tissue plates depending on the surface relief and solubility was studied in ectopic bone formation test. Calcium phosphate coating of titanium disks, made by the anodic spark (microarch) oxidation in 10% orthophosphoric acid with hydroxyl apatite particles, differed by the structure (thickness of coating, size of pores, and roughness) and solubility (level of in vitro oxidation of 1-week extracts of implants). Chemical (phasic and element) composition of the studied calcium phosphate coatings was virtually the same. The findings indicate that histogenesis is regulated by physicochemical characteristics of the implant surface. It seems that the osteogenic potential of calcium phosphate surfaces is largely determined by their relief, but not by pH of degradation products.