1995 Fiscal Year Final Research Report Summary
An Experimental Study of the Periapical Healing after Apexification on the Immature Pulpless Teeth
| Project/Area Number |
06454548
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Conservative dentistry
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| Research Institution | THE NIPPON DENTAL UNIVERSITY |
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Principal Investigator |
IGARASHI Masaru THE NIPPON DENTAL UNIVERSITY,SCHOOL OF DENTISTRY AT NIIGATA ASSOCIATE PROFESSOR, 新潟歯学部, 助教授 (90168104)
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| Co-Investigator(Kenkyū-buntansha) |
MIYASATO Tsuyoshi THE NIPPON DENTAL UNIVERSITY,SCHOOL OF DENTISTRY AT NIIGATA ASSISTANT, 新潟歯学部, 助手 (00239378)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Immature tooth / Pulpless tooth / Apexification / Periapical healing / Calcium hydroxide / Macaca irus / Animal experiment / Apical closure |
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| Research Abstract |
Periapical wound healing after apexification on immatured non-vital permanent teeth with bulunderbass canals were evaluated histologically. This investigation was undertaken on sound permanent teeth in three crab-eating young mondeys aged four approximately.
Under general and local anesthesia, access openings of the teeth were performed with rubber-dam isolation, then the coronal pulps were extirpated. Remnant root pulps were cauterized and coagulated with high frequency current, and then divided to two groups, one was infected group, and other was non-infected groop.
One week later, infected root canal treatment was started, and calcium hydroxide or FR-Ca paste was applicated to the canal after root canal disinfection. At the conclusion of the experimental period, 1,3,5 months, the animals were sacrificed by perfusion with neutral formalin. Decalcified serial paraffin sections were prepared and stained with hematoxylin-eosin, and observed by light microscopy.
The results obtained were as follows :
1. The pulp tissue which contacted with eletrode was coagulated, but at some distance from it vital pulptissues were still existent in alive.
2. The burn caused by a rise in temperature of the root conal was observed in the periodontal ligaments and alveolar bone on the immature tooth with thiner root canal wall, and external root resorption and/or ankylosis with the bone were observed.
3. After the apexification with calcium hydroxide on non-infected group, addition of severe osteo-dentin which filled up the canal space was observed at apex area.
4. Continual development of the root by osteo-dentin was observed, but abnormal formation of root apex and severe calcified of root canals were appeared.
In future, these results will be compared with infected groop, and details will be investigated further.
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