| 研究実績の概要 |
Surface roughness and chemical composition are vitally important factors in implants. The aim of this study is the fabrication and assessment of a new zirconia implant with embedded and fused zirconia beads on the surface.
For manufacturing of the zirconia substrates coated with zirconia beads, the zirconia powder pressed with 61 MPa pressure in the stainless mold, followed by pressing of the zirconia beads with two different diameters, 53 μm (B53) and 125 μm (B125), to the surface of zirconia tablet with 74 MPa pressure. The zirconia beads partially embedded into the un-sintered zirconia tablet surface. The prepared zirconia tablets with embedded zirconia beads on the surface were sintered at 1200°C for 12 hours. After sintering, a porous bead-fused surface was prepared on the zirconia disc.
The firmly adhered beads on top of the zirconia substrate surface The surface and cross-section microstructure was observed using optical microscope and preliminary evaluation confirmed that the beads adhered firmly to the surface.
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| 今後の研究の推進方策 |
To evaluate adhesive strength between the embedded and fused zirconia beads and the zirconia bulk, stainless steel rods with 4 mm diameter will bond to the rough surface of the zirconia substrate with acrylic super glue. An adhesion test will be performed at a cross-head speed of 2 mm/min by a universal testing machine (model 5566S, Instron Co., Canton, MA, USA) with a universal joint to ensure axial loading. The adhesive strength of the beads layer will be confirmed from the maximum recorded-load. The mean values of the adhesive strength and their standard deviation (SD) will be measured for ten samples.
For Microstructural and chemical characterizations, the field emission scanning electron microscope (FE-SEM: JSM-7500 FAM, JEOL, Tokyo, Japan) combined with EDS will be used for morphological, fractographical and elemental evaluation of the bead-fused zirconia samples at 15kV of accelerating voltage after the gold sputtering. The surface roughness of the samples will be determined by 3D laser microscope (VK- 9710K, Keyence, Osaka, Japan) according to ISO 4287. An average value of Rz will be calculated by linear roughness analyzing on the samples.
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