1994 Fiscal Year Final Research Report Summary
Hybridization and functionalization of biocompatible monomer by in situ polymerization in teeth.
| Project/Area Number |
05453213
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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 |
Biomedical engineering/Biological material science
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| Research Institution | Tokyo Medical and Dental University |
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Principal Investigator |
NAKABAYASHI Nobuo Tokyo Medical and Dental University, Institute for Medical and Dental Engineering, Professor, 医用器材研究所, 教授 (30014020)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Akihiko Tokyo Medical and Dental University, Institute for Medical and Dental Engineerin, 医用器材研究所, 助手 (30126263)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Biomaterials / Biocompatibility / Dental materials / Bonding / Dentin / Hybrid layr / 4-META / MMA / TBB resin |
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| Research Abstract |
In this project, the in vivo and in vitro tensile bond strengths of a biocompatible adhesive ; 4-META/MMA-TBB resin, to human dentin were compared and importance of the hybrid layr, which was created through in situ polymerization of the monomer in teeth, was investigated to obtaining durable bonding. Caries-free teeth present on patients and scheduled for extraction for orthodontic reasons were used. Tensile bond strength was evaluated and all specimens were sectioned immediately after bond testing, after polishing the debonded area or after treating the surfaces with HCl acid. Data were analyzed statistically, and no significant differences could be determined between third molars and first premolars, and in vivo and in vitro specimens. From scanning and transmission electron microscopic observation, widths (<plus-minus>5mum) of hybrid layrs and impregnation of adhesive monomers into 10-3 solution demineralized vital human dentin substrates were essentially similar to those observed in extracted samples. The adhesive resin penetrated tubules to form resin tags, unimpeded by intra-tubular fluid under physiologic pressure in intra-orally prepared specimens. A hybrid layn formed on resin tags to seal against microleakage and pulpal attack by bacteria and their by-products. An acid-resistant hybrid layr was also observed in enamel. Finally, hydroxyapatite crystals that were encapsulated by polymerized 4-META/MMA-TBB resin was observed at the bases of resin-reinforced hybrid layrs in the human dentin substrates. This observation is consistent with earlier findings and indicates the importance of the hybrid layr in maintaining durable dentin bond
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