Bone-Bonding Ability of Anodized Titanium Plate Loaded With Hydroxyapatite Particles
- PDF / 450,681 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 96 Downloads / 156 Views
1132-Z08-08
Bone-Bonding Ability of Anodized Titanium Plate Loaded With Hydroxyapatite Particles Mitsunobu Iwasaki1, Kohki Kudo1, Kazuki Shimada1, Kohji Matsuzaki2, and Chiaki Hamanishi2 1 Department of Applied Chemistry, School of Science and Engineering, Kinki University, 3-4-1 Kowakae, Higashi-Osaka, Osaka, 577-8502 Japan 2 Department of Orthopedic Surgery, School of Medicine, Kinki University, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka 589-8511 Japan ABSTRACT Submicron-sized hydroxyapatite (HAp) particles were loaded on the titanium plate by anodic oxidation over spark discharge voltage in HAp-containing bath. The biocompatibility and bioactivity were drastically improved by HAp deposition on the anodic oxide films. The affinity with living bone was the following order: anodized titanium plate with HAp > anodized titanium plate >> titanium. Bone-bonding strength between HAp-loaded titanium plate and living bone after 4 weeks’ implant was much higher than that of anodized titanium plate. INTRODUCTION Titanium is one of the most important biometallic materials because of its excellent biocompatibility, high mechanical strength and fracture toughness [1]. However, it is bio-inert and does not form chemical bonding to living bone. Therefore bioactive layer such as hydroxyapatite (HAp) on titanium surface is strongly required to give the bioactivity to titanium plate [2]. There are several preparation methods to form apatite coating on titanium plate: plasma spray coating [3], laser ablation, rf sputtering, sol-gel, and so on [4]. However, the materials prepared by the above methods have various problems such as decomposition of HAp, low coating speed, and low adhesion between Ti and HAp. Recently, it is reported that artificial bone with porous surface can be strongly connected to living bone because of the anchor effect [5]. Lately, thick anodized titanium films loaded with HAp were prepared by anodization in the electrolytic bath containing HAp nanoparticles [6]. This material resolves these above problems. In this paper, high bioactivity and biocompatibility of anodized titanium plate loaded with HAp are demonstrated by in vivo and in vitro experiments. EXPERIMENT A commercially available pure titanium plate served as a titanium substrate and anodized over spark discharge voltage under direct current in an electrolytic solution (Na3PO4-NaOHH2O2) with HAp particles (1-10 g, 0.1-0.5 micron in diameter). The titanium substrate was employed as a cathode as well as an anode with a distance of 5 cm between electrodes. The anodization was applied by two methods. First method (AO-Ti) is constant current density (Id = 2.0 Adm-2) under the maximum voltage at 150 V for 10 or 20 minutes. The other one is constant current density (Id = +2.0 Adm-2) with rectangle wave at 10-500 Hz (Pulse-AO-Ti) for 20 minutes. Powder X-ray diffraction (XRD; RIGAKU RINT 2000) was carried out using Ni-filtrated Cu-Kα radiation for determining crystal structures of AO-Ti and Pulse-AO-Ti.
Adhesive bonding strength between anodic oxide film and tit
Data Loading...
