Entity

Time filter

Source Type


Park I.-S.,Chonbuk National University | Lee K.-S.,Chonbuk National University | Shin G.-S.,Randuster Business Center Jeonbuk Technopark | Lyu S.-K.,Gyeongsang National University | And 2 more authors.
International Journal of Precision Engineering and Manufacturing | Year: 2013

A mini implant system made from Ti-6Al-4V alloy was used as the experimental material. The pull-out strength between the implant fixture and abutment was evaluated after the implant fixture and tapered abutment had been fixed by static compression loading, and hit with a mallet. Moreover, the fatigue limit was evaluated based on ISO/FDIS 14801:2003(E). In cases with compressive loading of 10, 50, 100, 150 and 200 N, the measured full-out load was 17.1 N, 33.6 N, 86.9 N, 99.7 N and 157.6 N, respectively. The full-out load measurements were 139.1 N and 195.6 N in the case of the mallet weight of 70 and 130 g, respectively (P < 0.05). The measured pull-out strength increased with increasing weight and number of mallet strokes, and the compression load. The compressive strength was examined according to the implant angle. The compressive strength in the 30° group was 532.2 ± 56.7 N, which was the highest value. On the other hand, the compressive strength in the 60° and 90° group was 156.7 ± 12.6 N and 117.3 ± 6.0 N, respectively. The fatigue life increased with decreasing applied strength level and the fatigue limit was 240 N. © 2013 Korean Society for Precision Engineering and Springer-Verlag Berlin Heidelberg. Source


Song K.-W.,Dental Design Co. | Park I.-S.,Chonbuk National University | Shin G.-S.,Randuster Business Center Jeonbuk Technopark | Lyu S.-K.,Gyeongsang National University | And 2 more authors.
International Journal of Precision Engineering and Manufacturing | Year: 2013

This study examined the fracture strength of 3-unit all-ceramic zirconia bridges treated with a melt-infiltration process of borosilicate glass. The zirconia specimens were milled with presintered yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) blocks. Before veneering the porcelain, borosilicate glass was infiltrated into the zirconia at 1,100°C for 1 hr. A 3-point flexural test was carried out at crosshead speed of 0.1 mm/min. The fracture surface and interface between the zirconia and veneer porcelain were observed by scanning electron microscopy. The fracture strength of the Y-TZP specimens was increased significantly by the melt-infiltration process of borosilicate glass (P < 0.05). The bond strength of the porcelain on zirconia was also improved significantly by meltinfiltration process of borosilicate glass (P < 0.05). The resistance to the initial chipping of the veneered porcelain in the 3-unit allceramic zirconia bridges was increased significantly by melt-infiltration process of borosilicate glass (P < 0.05). According to the microscopic observations of the fracture surface of porcelain, the glass-infiltrated zirconia group showed a rough fracture surface, whereas the sintered zirconia group showed a smooth fracture surface containing many pores. © 2013 Korean Society for Precision Engineering and Springer-Verlag Berlin Heidelberg. Source


Lee J.-J.,Chonbuk National University | Park I.-S.,Chonbuk National University | Shin G.-S.,Randuster Business Center Jeonbuk Technopark | Lyu S.-K.,Gyeongsang National University | And 3 more authors.
International Journal of Precision Engineering and Manufacturing | Year: 2014

The effect of polydopamine coated titanium such as surface roughness, wettability, cell growth and toxicity, and corrosion resistance. The polydopamine-coated titanium was successfully prepared from dopamine solution and bright polydopamine granules were randomly distributed on titanium surface after coating process. The surface roughness was not significantly decreased in the pure titanium (P>0.05), but significantly decreased (P<0.05) in the spark anodized titanium after the dopamine coating treatment. The contact angle of polydopamine-coated titanium surface was found to be lower than that of the untreated titanium surface. At the potentiodynamic polarization corrosion test, polydopamine-coated titanium has better corrosion-resistance than untreated titanium. The resistance of cytotoxicity is decreased by dopamine coating surface treatment (P<0.05). Findings from this research suggested that polydopamine coating offer a versatile approach for the titanium surface modification. © 2014 Korean Society for Precision Engineering and Springer-Verlag Berlin Heidelberg. Source


Li L.-H.,Chonbuk National University | Li L.-H.,University of Ulsan | Narayanan T.S.N.S.,Chonbuk National University | Kim Y.K.,Chonbuk National University | And 5 more authors.
International Journal of Precision Engineering and Manufacturing | Year: 2014

Magnesium and its alloys are potential candidate materials for use as absorbable implants due to their excellent biodegradability and biocompatibility. Reducing their rapid corrosion rate by alloying and surface modification has been the focus of many research programs. To improve the corrosion resistance and to impart coloration, pure Mg is modified by micro-arc oxidation (MAO) using electrolytes containing different concentrations of manganese (Mn). A porous and thick MAO coating layer consisting of MgO, Mg3(PO4)2 and Mg2SiO4 phases is deposited on Mg. The color of the MAO treated Mg is changed from light gray to brown with the addition of 0.015 M Mn to the base electrolyte. The MAO coatings prepared in this study offers an improved corrosion resistance for Mg. © 2014 Korean Society for Precision Engineering and Springer-Verlag Berlin Heidelberg. Source

Discover hidden collaborations