Yukari Iwaya

Kagoshima University, Kagosima, Kagoshima, Japan

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Publications (4)5.9 Total impact

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    ABSTRACT: The purpose of this study was to evaluate the effects of acid-etched titanium on the biological responses of osteoblast-like MC3T3-E1 cells. Four types of treatments (polishing, sandblasting, concentrated H2SO4 etching, and concentrated H2SO4 etching with vacuum firing) were carried out on the surfaces of commercially pure titanium (cpTi) disks. MC3T3-E1 cells were then cultured on the treated cpTi surfaces. Through surface roughness measurement and SEM analysis, it was found that the acid-etched surfaces showed higher roughness values than the sandblasted ones. Scanning electron microscope analysis showed that the cells on the disks treated with acid-etching and acid-etching with vacuum firing spread as well as the sandblasted ones. There were no significant differences in cell proliferation and collagen production on cpTi among the four different surface treatments. Based on the results of this study, it was concluded that etching with concentrated sulfuric acid was a simple and effective way to roughen the surface of titanium without compromising its biocompatibility.
    Full-text · Article · Jun 2008 · Dental Materials Journal
  • Seiji Ban · Yukari Iwaya · Hiroshi Kono · Hideo Sato
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    ABSTRACT: The purpose of this study was to characterize the etching behavior of titanium in concentrated sulfuric acid and discuss its application on surface modification of titanium for biological use. Commercially pure titanium (cpTi) plate was etched in 48% H2SO4 at RT -90 degrees C for 0.25-8 h. The weight loss was derived from the weight differences before and after etching. The surfaces after etching were characterized by surface roughness, X-ray diffractometry, and scannning electron spectroscopy. The apparent activation energy of the dissolution of cpTi into acid was derived from an Arrhenius plot of the rate of weight loss versus the acid temperature. The surface roughness of cpTi increased with the acid temperature and etching time. The surface roughness was strongly related to the weight loss. The weight loss increased drastically with the acid temperature after an initial period, which shortened with increasing acid temperature. The apparent activation energy for the dissolution of cpTi in H2SO4 was derived as 67.8 kJ/mol. This study indicates that etching with concentrated sulfuric acid is an effective way to modify the surface of titanium for biological applications.
    No preview · Article · Jan 2007 · Dental Materials
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    ABSTRACT: Commercially pure titanium (cpTi) was etched using three concentrated acids: 18% HCl, 43% H3PO4, and 48% H2SO4. The bond strengths between five types of veneering composite resin and eight cpTi treatments (involving combinations of sandblasting, acid etching in 48% H2SO4, and vacuum firing) were determined before and after 10,000 and 20,000 thermal cycles. There were no significant differences in the bond strength of resin to cpTi after etching in 48% H2SO4 at 90 degrees C for 15 minutes, at 60 degrees C for 15, 30, or 60 minutes, and after sandblasting with and without vacuum firing (p > 0.05); moreover, these treatments yielded the highest values. As for vacuum firing, it had no significant effect on resin bond strength to cpTi before or after 10,000 and 20,000 thermal cycles. We therefore concluded that acid etching in concentrated H2SO4 is a simple and effective surface modification method of titanium for bonding to veneering composite resins.
    No preview · Article · Jun 2006 · Dental Materials Journal
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    ABSTRACT: Concentrated H2SO4 acid was applied to pretreatment for the alkaline treatment of commercially pure titanium, and the effect of acid-etching on apatite-forming ability of alkaline-treated titanium in a simulated body fluid (SBF) was investigated. Characterization analysis revealed that the concentrated H2SO4 etching formed much amount of sodium titanate, resulting a large amount of formation of apatite in SBF. It is confirmed that the etching in concentrated H2SO2 enhance apatite-forming ability of alkaline-treated titanium.
    No preview · Article · Jan 2005 · Key Engineering Materials