Paper BI-WeM10
Roles of Anodic Oxide Layer on the Improvement of Cellular Response of Titanium Implant

Wednesday, December 5, 2018, 11:00 am, Room Naupaka Salon 6-7

Anodic treatment of titanium (Ti) has been used to improve its biocompatibility. The process leads to the formation of TiO₂ layer and the layer growth can be controlled by varying the processing voltage. Concomitantly, the surface roughness increases accompanying with the layer growth. Some researchers have believed that the enhanced biocompatibility through anodization is derived from the chemical property of TiO₂ itself, whereas other groups have insisted that the roughness increase relates with the biocompatibility. To obtain the valuable clue regarding this argument, in the present study, we prepared a TiO₂ layer with different roughness through the anodization in H₃PO₄ electrolyte with various voltages ranging from 5 to 500 V and thermal oxidation at 723 K in air. Thereafter, surface roughness and cellular response were compared to discuss the dominant property contributing the enhancement.

The surface image of the anodized substrates, observed by SEM, revealed that the surface roughness increased with increasing the voltage. To investigate the cellular response, MC3T3-E1 cells, an osteoblast-like cell line, were seeded on the sample surface and cultivated for 72 h, after which the numbers of the attached cells were counted. The numbers of the cells on the anodized surfaces were larger than those on an untreated and the thermally oxidized surfaces, whereas the difference depending on the processing voltage was hardly observed. Ii was conjectured that the enhanced biocompatibility is due to the anodized TiO₂ itself, of which surface property is different with that of TiO₂ prepared by thermal oxidation.