Chemical properties of toothbiushhed titanium restoration surface and chemical state of its abraded powder

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Titanium plate was toothbrused using two fluoride-free toothpastes, ETL and NSA, containing finer abrasive grains of amorphous silica and coarser abrasive gains of crystalline calcium hydrogen phosphate dihydrate, respectively. The micro morphology, chemical composition, and passive film structure of the brushed surface as well as abraded titanium debris were investigated by means of XGT,EPMA,SPM,and XRD.The results obtained are summarized as follows :1)Comet tail-like dimple pattern and hairline-like scratch pattern were observed in the ETL-and NSA-brushed surfaces. The latter surface was much rougher than the former one. Hie more acidic the toothpaste slurries, both the patterns became more vague, and the surfaces smoother. 2)Corresponding to the dimple pattern(ETL), Si was locally concentrated with higher amounts of oxygen, while along the scratched hairlines(NSA), Ca and P were concentrated with higher amounts of oxygen. The amounts of these elements from the abrasive materials decreased with the increasing acidity of the toothpaste slurries. 3)XPS analysis showed that Si existed as species like titanium silicate in the surface oxide film 4)While Ca and P existed in relatively deep surface of NSA, these elements in the outermost surface might exist as complicated species like titanate including Ca and P. 5)Fine titanium debris of 0.2〜0.3μm were found in the used slurries, some were isolated from, and the others attached to abrasives. 5)XPS spectrum of titanium in the used paste was broad and weak, but suggested the existence of reaction product of titanium with higher binding energy than TiO_2.6) XRD implied that Ca ions of calcium hydrogen phosphate dihydrate might be substituted by Ti ion.