Ti Oxide Films Formed by an Anodizing Process for Use in Dental Implants

Abstract

Anodic oxide films were formed on titanium using an electrolyte solution containing phosphoric acid for dental implants by an electrochemical method. The parameters of the oxidation process were current density and electrolyte concentration. The micro structural morphology, surface roughness, thickness of the oxide layer and the behavior of voltage-time curves were examined. The results show that the surface roughness, porosity size and the thickness of the oxide layer showed similar trends as the process parameters were changed. The surface morphology of the samples was observed for different current densities at a constant electrolyte concentration. The pore size, thickness and roughness of the anodic oxide films are directly proportional to the maximum voltage and the slope of the voltage to time transient (dV/dt) curves during the growth of the galvanostatic anode oxide film on plate type Ti.

Electrochemically assisted room‐temperature crack healing of ceramic‐based composites

“…In the Al 2 O 3 /Ti composites, the conductive Ti particles are randomly distributed but contact each other to percolate, resulting in a Ti network through which electric current can flow. This phenomenon is described elsewhere . However, only interconnected Ti particles can form a completely continuous pathway (Figure A); thus, electrical current flows through the composites via specific pathways and not all of the Ti particles can be oxidized.…”

“…Sample 30Ti, with a higher electrical conductivity and greater Ti content than 20Ti, seems to be more effective for the anodization; however, 20Ti, exhibits better crack‐healing ability. This is attributed to the differences in fracture toughness: 4.31 ± 0.16 and 4.14 ± 0.23 MPa·m 1/2 for 20Ti and 30Ti, respectively . Crack propagation in composite with higher fracture toughness is different leading to shorter crack length.…”

“…The preparation method of the Al 2 O 3 /Ti composites has been reported previously . Briefly, α‐Al 2 O 3 (0.2 μm; AKP‐53; Sumitomo Chemicals Co., Ltd., Tokyo, Japan) and TiH 2 (5‐10 μm; >99%; Kojundo Chemical Laboratory Co. Ltd., Sakado, Japan) with a 20 vol% (20Ti) and 30 vol% (30Ti) in the sintered composites were mixed by wet ball milling for 24 hours in super dehydrated ethanol with the purity of 99.5%.…”

“…The electrical resistivities were 8.04 × 10 −3 Ω·cm for 20Ti and 4.06 × 10 −3 Ω·cm for 30Ti. The electrical resistivity of composites was measured by the van der Pauw method which was described in detail in our previous report …”

“…Although anodic oxidation has been widely used for the surface modification of metals and the anodic oxidation of titanium or titanium alloys has long been a topic of intensive research, this is the first report on anodization for cracks healing in ceramic‐based composites at room temperature.…”