2002 Fiscal Year Final Research Report Summary
Development of focal infection model result from infected root canal-associated bacteria on compromised hosts.
| Project/Area Number |
12557161
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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 | 展開研究 |
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| Research Field |
Conservative dentistry
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| Research Institution | Osaka University |
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Principal Investigator |
EBISU Shigeyuki Osaka University, Graduate School of Dentistry, Professor., 大学院・歯学研究科, 教授 (50116000)
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| Co-Investigator(Kenkyū-buntansha) |
HIRAOKA Akira Osaka Medical Center for Cancer and Cardiovascular disease, The 5^<th> Internal Medicine, Chief Director., 第5内科, 部長(研究職)
KINOMOTO Yoshifumi Osaka University Dental Hospital, Assistant Professor., 歯学部附属病院, 講師 (10252694)
NOIRI Yuichiro Osaka University, Graduate School of Dentistry, Research Associate., 大学院・歯学研究科, 助手 (50218286)
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| Project Period (FY) |
2000 – 2002
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| Keywords | compromised-animal / immunosuppressant / bacterial biofilm / infected root canal / focal infection / bacteremia / periapical lesion / planktonic bacteria |
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| Research Abstract |
Correlation between Cyclosporin A (CsA)-induced immunosuppression and untreated or residual periapical lesions has been investigated 3 dimensionally with time, and histopathological analysis were performed. CsA treatment significantly inhibited lesion expansion.. Agter withdrawal of CsA, the lesion increased in size to a same extent in a control group. In addition, histopathological observation revealed that the difference of CsA administration volume did not affected much. However, CsA treatment induced intercellular substance in fibrous tissue to be voluminous, especially in 20mg/Kg/day administration group.
In vitro, biofilm forming capacity of 7 infected root canal-associated bacterial (RCB) species to gutta-percha points (GP) was investigated morphologically. Enterococcus faecalis formed most frequently biofilm, but Fusobacterium uncleatum or Propionibacterium acnes did not form it at all. The biofilm forming capacity of 5 RCB species to extraradicular GPs on beagle dogs were evaluated by bacteriologic technique. E. faecalis identified in 71.4% of the examined samples, and was most suitable biofilm forming bacterium in extraradicular area. According to their results, compromised-animals to be administrated methylpredonisolon acetate were prepared for investigation of bacteremia by which planktonic bavteria detached from extraradicular E. faecalis biofilm caused. For 4 weeks administration, bacteremia was not induced, whereas planktonic E. faecalis cells insertion of about 10^3 times biofilm bacteria on GP in vitro in the periapical lesion became continuously bacteremia. Drug concentration and administration period were further studied, and we are continuously searching bacteremia caused by extraradicular biofilm on compromised-animal.
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Research Products
(13 results)
