| Project/Area Number |
02454436
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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 | Osaka University |
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Principal Investigator |
TORII Mitsuo Osaka Univ., Fac. Dentistry, Assoc. Prof., 歯学部, 助教授 (30116066)
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| Co-Investigator(Kenkyū-buntansha) |
TAKESHIGE Fumio Osaka Univ., Dental Hospital, Research Asst., 歯学部附属病院, 助手 (60206969)
YASUNAGA Tetsuya Osaka Univ., Fac. Dentistry, Research Asst., 歯学部, 助手 (70182342)
KAWAI Keiji Osaka Univ., Dental Hospital, Asst. Prof., 歯学部附属病院, 講師 (40204664)
TSUCHITANI Yasuhiko Osaka Univ., Fac. Dentistry, Prof., 歯学部, 教授 (40028709)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥6,100,000 (Direct Cost: ¥6,100,000)
Fiscal Year 1991: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1990: ¥5,100,000 (Direct Cost: ¥5,100,000)
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| Keywords | Antibacterial Composite Resin / Non-releasing Antibacterial Agent / Anti-plaque Activity / 抗菌性レジン |
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| Research Abstract |
In order to give composite resin enduring antibacterial activity without a fall of mechanical properties, we attempted to develop the non-rele asing antibacterial composite resin. An antibacterial monomer, which is the combination of antibacterial agent and polymerizable group, is expected to bind chemically to base resin of composite resin and give the non-releasing antibacterial activity.
Two kinds of antibacterial monomer were synthesized by combining antibacterial agent and methacryl group without decrease of antibacterial activity. One is 2methacryloyloxyethyl-p-hydroxy benzoate (MBA) and another is 12methacryloyloxydodecylpyridinium bromide (MDPB). When these two antibacterial monomers were added in composite resin. -the resin showed non-releasing antibacterial activity, that is, the resin released very few antibacterial agent which was far less than its MIC, however, killed bacteria which touched the surface of the resin.
The antibacterial activity of MBA was low and it was necess
… More
ary to add MBA more than 1 % (wt/wt) (final concentration) of composite resin to get sufficient antibacterial activity. At such a high concentration, unnegligible amount of MBA remained unpolymerized and it was released from composite resin. We decided that MBA was of no practical use.
MDPB possessed pretty strong antibacterial activity and the composite resin containing 0.1 - 0.2 % (wt/wt) (final concentration) MDPB showed clear antibacterial activity. The composite resin containing 0.1 % MDPB did not release detectable amount of MDPB (detection limit : 1 ug/ml) when it was immersed in either water, ethanol or n-heptan for six months. The composite resin containing 0.2 % MDPB also did not release MDPB when it was immersed in water or n-heptan, but 1.17 ug/ml of MDPB was released in ethanol after five months. We think this degree of release is practically negligible. The MDPB containing composite resin gathered clearly less amount of artificial plaque compared to control resin. Both antibacterial and anti-plaque activity of MDPB containing composite resin did not change after three-month immersinon in water. There was no significant difference between the mechanical properties of the resin and those of control resin after three months immersion in water.
As shown above, composite resin was given non-releasing antibacterial activity by adding MDPB. Less
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