2005 Fiscal Year Final Research Report Summary
Application of titanium alloys to porcelain fuse to metal crown.
| Project/Area Number |
15390586
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
補綴理工系歯学
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| Research Institution | Tohoku University |
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Principal Investigator |
YODA Masanobu Tohoku University, Graduate School of Dentistry, Associate Professor, 大学院・歯学研究科, 助教授 (70005073)
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| Co-Investigator(Kenkyū-buntansha) |
KIMURA Kohei Tohoku University, Graduate School of Dentistry, Professor, 大学院・歯学研究科, 教授 (40108551)
TAKADA Yukyo Tohoku University, Graduate School of Dentistry, Associate Professor, 大学院・歯学研究科, 助教授 (10206766)
OKUNO Osamu Tohoku University, Graduate School of Dentistry, Professor, 大学院・歯学研究科, 教授 (50014080)
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| Project Period (FY) |
2003 – 2005
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| Keywords | titanium alloy / porcelain fused to metal crown / bond strength to porcelain / thermal expansion / shrinkage |
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| Research Abstract |
Titanium is an attractive dental restorative material because of its excellent characteristics, however it is difficult to cast. We have been investigating some beta-stabilized titanium alloys which have lower fusion temperatures than pure titanium. For dental clinical use, these alloys must be able to bond to dental porcelains because of the esthetic demands of dentistry.
This time, we investigated the Au-1.6wt% Ti alloy. The bond strength to porcelain and fitness of porcelain fused to metal crown were evaluated.
The coefficient of thermal expansion of the Au-1.6 wt% Ti alloy showed a close value to that of conventional precious metal alloys for porcelain fused to metal crown. Bonding strength of the Au-1.6 wt% Ti alloy was higher than 25 MPa, the minimum value specified in ISO 9693. EPMA observation showed an accumulation of Ti and O contents on the alloy side at the metal-ceramic interface.
Then we investigated the effect of abutment finish-line curvature on the fit of crowns. The metal ceramic crowns cast in Au-1.6 wt% Ti alloy had accuracy as good those as-cast in control of conventional precious metal alloys for porcelain fused to metal crown.
In the as-cast specimens, the greater the finish line curvature, the mesial and distal margins of copings exhibited larger gaps than labial and lingual margins.
After porcelain application, for metal ceramic crowns of the facial-veneered type, the greater the finish line curvature, the larger the labial marginal gap became.
Au-1.6wt% Ti alloy had equivalent accuracy to those that cast in control precious alloy, and the abutment finish-line curvature had a significant effect on the marginal fit of porcelain fused to metal crowns.
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