Enhancement of bone growth in titanium fiber mesh by surface modification with hydrogen peroxide solution containing tantalum chloride.

Abstract

A tight fixation between bone and implant materials is of great importance for a successful outcome of procedures such as total knee arthroplasty (TKA) and total hip arthroplasty (THA). Surface modification of titanium metal and titanium alloy is one of the attractive methods to improve the biological affinity of orthopedic prostheses. Recent studies reported that titanium substrates were provided with bone-bonding ability, that is, osteoconductivity, through a chemical treatment with hydrogen peroxide solution containing tantalum chloride. The present study investigated the histological and mechanical effects of such treatment of the surface of titanium fiber mesh. Titanium alloy rods of 7.6 x 7.6 x 20 mm that had a titanium fiber mesh of 250 microm were implanted bilaterally into the distal aspect of the femur of adult beagle dogs. At 3, 5, and 8 weeks after implantation, the rods were removed to examine their bonding strength and histological compatibility with bone. Bonding strength was evaluated by the pull-out test. The bonding strength of the treated specimen with bone increased with time, and was faster than that of untreated specimens. At 8 weeks postoperative, the bonding strength of both the treated and untreated specimens became almost equal. The amount of newly formed bone on and in the titanium fiber mesh was significantly increased by the chemical treatment (p<0.05). The rate of bone formation in the fiber mesh was accelerated after chemical treatment. These results indicated that the surface treatment enhanced bone formation in the initial stage thank to the osteoconductive property of the titanium fiber mesh conferred by the chemical treatment so that faster bonding strength was achieved. Surface treatment providing titanium mesh with osteoconductivity has the advantages of the fast healing and tight bonding for prostheses in TKA and THA.