| Project/Area Number |
05557085
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| Research Category |
Grant-in-Aid for Developmental 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 | TOHOKU UNIVERSITY |
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Principal Investigator |
HORIUCHI Hiroshi TOHOKU UNIVERSITY,DENTISTRY,PROFESSOR, 歯学部, 教授 (00013962)
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| Co-Investigator(Kenkyū-buntansha) |
ISHIHATA Hiroshi TOHOKU UNIVERSITY,DENTAL HOSPITAL,ASSISTANT, 歯学部・附属病院, 助手 (40261523)
TAMAZAWA Kaoru TOHOKU UNIVERSITY,DENTAL HOSPITAL,LECTURER, 歯学部・附属病院, 講師 (00124602)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥5,400,000 (Direct Cost: ¥5,400,000)
Fiscal Year 1994: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1993: ¥4,000,000 (Direct Cost: ¥4,000,000)
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| Keywords | Plasma / Sterilization / Oxygen |
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| Research Abstract |
The autoclave has been widely used in dentistry as an effective method to sterilize instruments and materials. Corrosion of carbon steel instruments and the decomposed bacterial substances remaining on the surface of the instruments have been the problem with the autoclave. The purpose of this study was to investigate the characteristics of an oxygen plasma reactor as the dental sterilizer. The plasma reactor used was type PR-31 (YAMATO Sci.Co.Ltd) . High frequency electric field of 13.56MHz was applied to the glass cham ber by capacitance coupling. Oxygen flow in the chamber was 50ml/min to 100ml/min.
Internal temperature of a glass tube (outer diameter : 2.00mm, internal diameter : 0.95mm) inserted into the pla sma was measured by the iron-constantan thermocouple(diameter : 0.08mm) . The temperature increased in accordance with the out put power and duration of the application of the plasma
Metal plates (5*20*0.5mm) were u sed as the test specimens. Whole saliva (circa 10000 to 1000000CFU) was place d on the specimen and dried for 30min. The effect was estimated by the cult ured specimens in the brain heart infusion broth. When the plasma treatment of 300W (10min) was applied, all of the 25 specimens resulted in negative culture.
New carbon steel burs were treated by plasma, or autoclave sterilization or dry heat sterilization. Obsevation of the surfaces of these burs under a scanning electron microscope revealed that plasma treatment produced the cleannest surface.
In conclusion, the oxygen plasma treatment has possibility to be used as a dental sterilizer.
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