| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
Fiscal Year 2011: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2010: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2009: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
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| Research Abstract |
The purpose of this study was to compare the fatigue and tensile strengths of radicular dentin. Dentin slabs were prepared along the radicular tooth and trimmed into dumbbell-shaped specimens. Subsequently, fatigue and tensile tests were performed. The staircase method was employed to determine fatigue strength and its standard deviation. Mean fatigue strength and tensile strength were 44.3 ± 5.0 and 84.4 ± 8.3 MPa, respectively. The fatigue strength of radicular dentin was only approximately one half of the tensile strength. Additionally, fracture surfaces were observed by scanning electron microscopy. In engineering materials, fatigue failures are often facilitated by cyclic crack extension, which is identified by a series of self-similar inflections on the fracture surface regarded as “striations”. We confirmed that striations spacing on fracture surfaces of radicular dentin ranged from approximately 3 to 10 μm.
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