2004 Fiscal Year Final Research Report Summary
Studies on cutting aspect and development of rotary endodontic instruments for low-speed engine
| Project/Area Number |
14370621
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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 |
Conservative dentistry
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| Research Institution | The Nippon Dental University |
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Principal Investigator |
KATSUUMI Ichiorh The Nippon Dental University, School of Dentistry at Tokyo, Professor, 歯学部, 教授 (50120639)
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| Co-Investigator(Kenkyū-buntansha) |
MAEDA Munehiro The Nippon Dental University, School of Dentistry at Tokyo, Associate Professor, 歯学部, 助教授 (10219280)
OGURA Yoko The Nippon Dental Univertisy, School of Dentistry at Tokyo, Instructor, 歯学部, 助手 (20366769)
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| Project Period (FY) |
2002 – 2004
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| Keywords | rotary cutting instrument / root canal preparation / cutting torque / round bur / Peeso reamer / engine reamer / ERT file / nickel-titanium rotary instrument |
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| Research Abstract |
A computer-controller torque testing device, has been designed and manufactured, which can cut, record and analyze in different testing modes such as continuous rotation and repeated rotation. By using this device, cutting tests have been performed on various types of instruments for enlargement of root canal orifice such as Peeso reamer in addition to the burs for cutting tooth substance used in endodontic treatment to root canal model made of resin and to extracted tooth. The cutting tests have also been performed on engine reamer, engine-driven RT file and various types of instruments for root canal preparation made of nickel-titanium. The results of the tests were generally as follows:
1. Cutting torque of round bur was influenced by the size of bur and by the number of cutting operations, and the results of the tests revealed that the increase of torque was caused by the decrease of the sharpness of the instrument due to wearing of the instrument. Also, sterilization process by hea
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ting exerted influence on the decrease of the sharpness of the cutting instrument.
2. Cutting torque of the instrument for enlargement of root canal orifice such as Peeso reamer was closely related to the number of revolutions and the pressing rate of the instrument. Also, configuration of the tip of the instrument and cross-sectional shape of the blade gave influence on the cutting.
3. The cutting of root canal by engine reamer was significantly influenced by the number of revolutions of the instrument, while the enlargement of the root canal orifice did not give influence on the cutting in the direction toward root canal tip.
4. The aspects of the cutting of root canal by the engine-driven RT file were diverse due to taper and diameter of the instrument and to the form of root canal, but the root canal could be cut with high efficiency. The aspects of cutting of various types of instruments made of nickel-titanium showed a trend similar to that of the engine-driven RT file, while the cutting was performed not very efficiently in most cases. The cutting was strongly influenced by the form of the instrument tip and by cross-sectional shape of the blade. Less
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Research Products
(12 results)
