| Co-Investigator(Kenkyū-buntansha) |
FUKUDA Hideaki Inst.Biomater. Bioeng Tokyo Medical and Dental University., assistant Researcher, 生体材料工学研究所, 助手 (50014163)
TAKAKUDA Kazuo Inst.Biomater. Bioeng Tokyo Medical and Dental University., Associate Professor, 生体材料工学研究所, 助教授 (70108223)
MIYAIRI Hiroo Inst.Biomater. Bioeng Tokyo Medical and Dental University, Professor, 生体材料工学研究所, 教授 (50013892)
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| Research Abstract |
A design of retainer of a resin-bonded partial denture is depended on mechanical properties. This study examined tensile adhesive strength, fracture toughness (double cantilever beam (DCB) test) and durability (4/60-degree C thermal-cycling test (5000 cycles) and DCB test under repeated constant displacement) on five commercially available adhesive resins (SB,SBO,PV,BR and ID). The major findings were as follows. When classified roughly in-group of SB without filler and group of PV, BR and ID with filler, that adhesive strength was almost similar. However, a value of fracture toughness of SB showed more than ten times of value of PV, BR and ID, and a considerable difference was recognized. Thus, the fracture toughness is greatly influenced filler content. About adhesive strength after thermal cycling test, the value of SB decreased comparing with their values of SBO, PV and BR.About fracture toughness after thermal-cycling test, the value of SB considerably decreased comparing with their values pf PV, BR and ID to decrease inconsiderably, and the fracture mode changed into interfacial fracture from cohesive fracture. Thus, it was found that adhesive strength and fracture toughness differed physically in mechanical property. In DCB test under repeated constant displacement, a value of crack propagating rate of PV was considerably larger than that of SB.Accordingly, for abutment tooth swaying comparatively, an adhesive resin with filler was not pleasing. From these fundamental testing results, in a long-term life design of resin-bonded partial denture, it was suggested that selection of adhesive resin with filler was not desirable. Therefore, on the basis of these mechanical properties of adhesive resin, it was important to select an adhesive resin to be reasonable to a resin-bonded partial denture.
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