| Project/Area Number |
11470416
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
補綴理工系歯学
|
|---|
| Research Institution | HIROSHIMA UNIVERSITY |
|---|
Principal Investigator |
MATSUMURA Masanobu (2001) Hiroshima University, Graduate School of Engineering, Professor, 大学院・工学研究科, 教授 (40034342)
趙 翰燮 (1999-2000) 広島大学, 工学部, 助教授 (00253112)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
HAMADA Taizo Hiroshima University, Faculty of Dentistry, Professor, 歯学部, 教授 (50034244)
松村 昌信 広島大学, 工学部, 教授 (40034342)
|
|---|
| Project Period (FY) |
1999 – 2001
|
| Project Status |
Completed (Fiscal Year 2001)
|
| Budget Amount *help |
¥5,600,000 (Direct Cost: ¥5,600,000)
Fiscal Year 2001: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2000: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1999: ¥3,800,000 (Direct Cost: ¥3,800,000)
|
|---|
| Keywords | Dental resin material / Dental metallic material / Repeated collision test / Anti erosion-corrosion property / 繰返し衝突試験 / 歯科材料 / すき間腐食 / 微生物腐食 / 衝突滑走摩耗 / 摩耗腐食 / ガルバニック腐食 |
|---|
| Research Abstract |
The purpose of this investigation is to develop testing methods to evaluate dental materials that are exposed in mouth to the combined attack of microbe corrosion and mechanical forces that are caused through the collision of teeth.
1. The determination of dynamic wear condition : Stresses which are originated on teeth while chewing soft or hard foods were determined by use of a load sensor (Tekscan) to obtain the extent of the maximum load, loading speed and the contact duration, which were ranged from 4-13 kgf, 0.03-0.07 kgf/ms, 420-500 ms respectively.
2. The degradation process of dental materials and the index of degradation : The delinquent in teeth meeting due the decrease in teeth height was taken up so that the decrease in the teeth height was chosen as the index of degradation.
3. Development of testing method : As to metallic materials, the teeth meeting were simulated through the combination of a flat plate (specimen) and a sphere (Al_2O_3). Repeated load was applied through t
… More
he sphere to the specimen to produce an indentation on the surface of which diameter is proportional to the depth of indentation, that is, the decrease in teeth height.
It increased with the test duration as an exponential function of loading frequency, which revealed some relation with the delayed movement of dislocation. Those test results obtained in a 3 % NaCl solution were proved to represent well the characteristic behavior of metallic materials that are exposed to the combined attack of wear and corrosion.
As to dental resin materials, a whole piece of false tooth was used as test specimen because it is a composite that consists of three different types of resin. Repeated collision test revealed firstly that the decrease in teeth height is caused not through wear but through the deformation of whole tooth piece, secondly that the deformation behavior changes its manner at the collision frequency of about 50000 times, and thirdly that the repeated collision test with low load reveals a characteristic behavior of material different from that of a single time loading test with a much higher load.
4. Basing on the test results, a new test method for the dental materials in mouth environment were proposed. Less
|
