高密度フィラー含有ハイブリッド型硬質レジンの天然歯との衝撃滑走摩耗試験

抄録

New types of composite resins for crown and bridge were recently developed and put on the market. One of them is a highly filled hybrid resin (ESTENIA, Kuraray) including 92 wt% (82 vol%) of ceramic particles. It is claimed that the resin much improved in hardness and strength is available for posterior crown and bridge. The present study examined the wear behavior of this resin when opposed by tooth enamel by means of impacting-sliding wear test, comparing with three kinds of materials for posterior use, porcelain, Au-Ag-Pd alloy and restorative composite resin. A hemispherical upper specimen and a flat lower specimen were prepared with each of the material and tooth. The upper specimen made of each material dropped and slid on the lower specimen made of tooth, or vice versa, for 10,000 times under a given load of 500 gf in artificial saliva. The Knoop hardness number was the largest in porcelain and the next in tooth enamel, Au-Ag-Pd alloy, hybrid resin and restorative resin, in that order ; however, the wear resistance was not dependent on the hardness in this test. The combination of porcelain and tooth showed significantly severe wear in both the specimens. The observation of the worn surface aspects revealed that the superficial cracking of them might induce their wears. There were no significant differences in wear among Au-Ag-Pd alloy-enamel, restorative resin-enamel and tooth-tooth. The highly filled hybrid resin exhibited the mixed wearing modes of porcelain and restorative resin. The combination of highly filled hybrid resin and tooth showed larger wears than tooth-tooth but significantly smaller than porcelain-tooth, and the hybrid resin seemed to be more favorable than porcelain for esthetic posterior crown and bridge.