Effects of acid-treatment conditions on the surface properties of the RBM treated titanium implants / 대한치과재료학회지

The purpose of this study was to evaluate the effect of acid-treatment conditions on the surface properties of the RBM (Resorbable Blast Media) treated titanium. Disk typed cp-titanium specimens were prepared and RBM treatments was performed with calcium phosphate ceramic powder. Acid solution was mixed using HCl, H2SO4 and deionized water with 4 different volume fraction. The RBM treated titanium was acid treated with different acid solutions at 3 different temperatures and for 3 different periods. After acid-treatments, samples were cleaned with 1 % Solujet solution for 30 min and deionized water for 30 min using ultrasonic cleanser, then dried in the electrical oven (37℃). Weight of samples before and after acid-treatment were measured using electric balance. Surface roughness was estimated using a confocal laser scanning microscopy, crystal phase in the surface of sample was analyzed using X-ray diffractometer. Surface morphology and components were evaluated using Scanning Electron Microscope (SEM) with Energy Dispersive X-ray spectroscopy (EDX) and X-ray Photoemission Spectroscopy (XPS). Values of the weight changes and surface roughness were statistically analyzed using Tukey-multiple comparison test (p=0.05). Weight change after acid treatments were significantly increased with increasing the concentration of H₂SO₄ and temperature of acid-solution. Acid-treatment conditions (concentration of H₂SO₄, temperature and time) did not produce consistent effects on the surface roughness, it showed the scattered results. From XRD analysis, formation of titanium hydrides in the titanium surface were observed in all specimens treated with acid-solutions. From XPS analysis, thin titanium oxide layer in the acid-treated specimens could be evaluated. Acid solution with 90℃ showed the strong effect on the titanium surface, it should be treated with caution to avoid the over-etching process.

The effect of veneer on the marginal fit of the copings using different materials / 实用口腔医学杂志

Objective:To compare the marginal fit changes between after-and before-veneering of the copings using three kinds of materials:gold alloy,cp titanium and Ni-Cr alloy,so as to determine whether the fit changes was influenced with the veneer and their clinical significance.Methods:24 maxillary incisor acrylic resin PFM abutments fabricated by machine with the consolidated standard were divided into three groups,each abutment was waxed-up,invested,and casted with three kinds of materials:gold alloy,cp titanium and Ni-Cr alloy.For all groups,the copings were repositioned on their respective abutments,the marginal fit values of four points of each coping were measured.Furthermore,after three groups of copings were veneered with recommended porcelain,marginal fit values of same point of each abutment were remeasured.SAS software was used to carry out statistical analysis.Results:One way analysis of variance of marginal fit values revealed significant differences between before and after veneering in three groups,and the marginal fit value enhanced after veneered.Among three groups,cp titanium group had a significant difference when compared with other two groups(P