치과 임플란트용 Ti-6Al-4V 합금 표면의 나노튜브 제조 및 세포부착 특성

Abstract

Although titanium and titanium-based implants are widely used in different fields, the nature of uses in dentistry requires the implants to possess good mechanical strength, easy malleability, and excellent surface adhesion properties to facilitate bonding with bones. Bonding between titanium surface and the biomolecule is an important factor for biocompatibility and properties of adhesion, morphology, cell function, and cell hyperplasia are affected by the surface characteristics of biomaterial. In this study, fabrication and cell attachment characteristics of nanotubes on the surface of Ti-6Al-4V dental implant alloy have been investigated. TiO2 nanotubes were formed on the Ti-6Al-4V alloys by anodic oxidation. The electrolyte solution was prepared by adding H3PO4 solution to 0.8 wt% NaF solution and then stirred with a magnetic stirrer. With a platinum electrode and a saturated calomel electrode, Electrochemical experiments were performed using a conventional three-electrode configuration. Anodic oxidation was carried out using a scanning potentiostat, and all experiments were carried out at room temperature. Crystallization treatment of nanotube surface was at 450 ℃ for 3hr. MC3T3-E1 cell culture was performed with MC3T3-E1 mouse osteoblasts for 2 days. Microstructure of the alloys and nanotube surface were observed by optical microscope(OM), field emission scanning electron microscope(FE-SEM), and crystallization of nanotube was identified by X-ray diffractometer(XRD). The results were as follows. 1. The resulting round, closed-bottom nanotubes mainly consisted of chemically bonded TiO2 with diameters ranging from 50 to 200 nm, and with thickness of 6 nm, which consisted of amorphic structures. 2. The nanotube diameter and thickness were increased by anodic oxidation time and voltage. 3. In as-anodized nanotubes typically have an amorphous structure, whereas nanotubes converted to mixture phases of anatase and rutile after crystallization treatment. In conclusion, the formation of the nanotube structure on the Ti-6Al-4V alloy significantly increased the surface area, which could be useful for the adsorption and adhesion enhancements of cells and could be applicated for drug delivery system.