Adhesion of hollow calcium-deficient hydroxyapatite microspheres onto titanium

Microcapsules containing active drugs, e.g. an antimicrobial agent, with a hydroxyapatite (HAp) shell are expected to prevent infection and to improve osseointegration simultaneously when used as implant materials. This study was conducted to investigate the effects of etching with hydrofluoric acid (HF) to change the surface morphology of titanium in cases of adhesion of calcium-deficient HAp microspheres onto titanium. The microspheres were mixed with Hanks' balanced salt solution (HBSS) to prepare slurry; the slurry was then put between two titanium disks that had been etched and kept soaking in HBSS for seven days at 310 K. The coverage and the degree of adherence of the microsphere were evaluated using electron probe microanalysis. The etching at an HF concentration of 0.10 mol/L caused the greatest adhesion. Changing the temperature between 303 and 323 K showed a tendency for the degree of adherence to increase.