Mechanical stability of two-step chemically deposited hydroxyapatite coating on Ti substrate: Effects of various surface pretreatments

作者：Zavgorodniy Alexander V^*; Borrero Lopez Oscar; Hoffman Mark; LeGeros Racquel Z; Rohanizadeh Ramin

来源：Journal of Biomedical Materials Research Part B: Applied Biomaterials , 2011, 99B(1): 58-69.

DOI：10.1002/jbm.b.31872

• hydroxyapatite coatings
• titanium implants
• scratch tests

The success of implants in orthopaedic and dental load-bearing applications crucially depends on the initial biological fixation of implants in surrounding bone tissues. Using hydroxyapatite (HA) coating on Ti implant as carrier for bone morphogenetic proteins (BMPs) may promote the osteointegration of implants; therefore, reduce the risk of implant failure. The goal of this study was to develop an HA coating method in conditions allowing the incorporation of protein-based drugs into the coating materials, while achieving a mechanical stable coating on Ti implant. HA coatings were deposited on six different groups of Ti surfaces: control (no pretreatment), pretreated with alkali, acid, heat at 800 degrees C, grit blasted with Al(2)O(3), and grit blasted followed by heat treatment. HA coating was prepared using a two-step procedure. First step was the chemical deposition of a monetite coating on Ti substrate in acidic condition at 75 degrees C and the second step was the hydrolysis of the monetite coating to HA. Coatings were characterized by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The roughness of substrates and coatings was measured using profilometry technique. The mechanical stability of the coatings deposited on the pretreated substrates was assessed using scratch test. The coatings deposited on the grit-blasted Ti surface demonstrated superior adhesive properties with critical shearing stress 131.6 +/- 0.2 MPa.

• 出版日期2011-10