2002 Fiscal Year Final Research Report Summary
A STUDY ON THE MECHANISUM OF TOOTH FRACTURE DUE TO MASTICATORY PRESSURE
| Project/Area Number |
12671859
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | OHU UNIVERSITY |
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Principal Investigator |
TAKATSU Toshio OHU UNIVERSITY, SCHOOL OF DENTISTRY, PROFESSOR, 歯学部, 教授 (70013985)
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| Co-Investigator(Kenkyū-buntansha) |
KOUROKU Nobuo OHU UNIVERSITY, SCHOOL OF DENTISTRY, INSTRUCTOR, 歯学部, 助手 (80275627)
KIKUI Tetsuya OHU UNIVERSITY, SCHOOL OF DENTISTRY, LECTURER, 歯学部, 講師 (00254871)
SATOH Masaaki OHU UNIVERSITY, SCHOOL OF DENTISTRY, ASSOCIATE PROFESSOR, 歯学部, 助教授 (80226000)
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| Project Period (FY) |
2000 – 2002
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| Keywords | tooth fracture / fractured tooth / fatigue test / fatigue fracture |
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| Research Abstract |
This study was performed on the following two parts.
1. Experimental fatigue fracture test using the compressive stress cycling apparatus
Occlusal cavities were mesio-dostally or bucco-lingually prepared in the human extracted upper premolars. Strain gauges were attached to the tooth 1mm below the cavity. Then, increasing compressive load was repeatedly applied to the cavity until the tooth fractured, using the fatigue test apparatus originally designed in our department. Measurements were performed on strained amount of the tooth, stress repeated number and final load value on fracture. Consequently, two types of the cavity were found remarkably differed in fracture resistance to the repeated stress, namely up to approximately 14.0×10^4 cycles for mesio-distal cavity and approximately 1.1×10^3 cycles for the bucco-lingual cavity. SEM observation of the experimentally fractured surface indicated the seemingly brittle and rapid fracture patterns.
2. Observation of the fractured tooth fragments in vivo
Sixteen subjects in total were used. Most of them had been endodonticly treated and restored. They were subjected to the optical microscopy, obtaining the finding that most of them fractured in rapid producing the gross and brittle fracture patterns.
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