Electrochemical Characteristics of TiN and HA Coated Dental Implant Fixture

Electrochemical Characteristics of TiN and HA Coated Dental Implant Fixture
Y.-M. KO, and H.-C. CHOE, Chosun University, Kwangju, South Korea
2005
IADR
Objectives: Ti alloys widely used as dental implant materials because of its suitable mechanical properties, good corrosion resistance and excellent biocompatibility. In this study, in order to increase corrosion resistance and biocompatibility of dental implant, the electrochemical characteristics of TiN and HA coated dental implant fixture were investigated using various electrochemical methods.
Methods: Pure Ti and Ti-6Al-4V alloys were fabricated by using a vacuum induction furnace and homogenized for 24hr at 1050oC. The implant fixtures were made by lathe machine for specimen. The compacted tooth ash was used as HA coating target. The coating on the surface were carried on using EB-PVD method. Electrons were accelerated by high voltage of 4.2kV with 80 ~ 120mA on the deposition materials at 350oC in 2x10-6 torr vacuum. The surface, coated layer and corrosion morphology were analyzed using FE-SEM and AFM. The corrosion behaviors of the samples were examined through potentiodynamic and cyclic potentiodynamic method in 0.9% NaCl solutions at 36.5oC.
Results: AFM surface morphology of TiN coated fixture showed lower roughness than that of tooth ash coated plates. The corrosion and pitting potential of the TiN coated fixture is comparatively higher than that of non coated fixture, whereas the passivation current density was smaller, indicating the good protective effect resulting from more compact and homogeneous layer formation. Pitting corrosion showed apparently in crest and root of screw for non-coated fixture, but in the case of TiN and HA coated samples, pit did not appeared in crest and root of screw. The number of pits which act as a site of fatigue fracture crack decreased in the crest and the root of screw.
Conclusions: It might be possible to prolong the fatigue fracture life of dental implant fixtureby TiN and HA coating. Supported by KOSEF(R01-2003-000-10515-0)