4种纤维桩的弯曲强度和显微结构的研究

目的 测试不同纤维桩的弯曲强度,并研究纤维桩弯曲强度与结构特征之间的联系。方法 选择4种品牌的纤维桩进行研究,D.T.Light-Post(BISCO),Pare PostTaper Lux(Coltene/Whaledent),LuxaPost(DMG),国产纤维桩(实德隆)各6根,随机选取5根进行三点弯曲测试,剩余1根及每种品牌中弯曲测试结果最高和最低者用于扫描电镜分析。结果 4种纤维桩的断裂载荷在127.80～157.40N,弯曲强度在820.03～937.95MPa,纤维/基质比值范围为54.56%～78.68%。各项分析结果显示纤维/基质比值与弯曲强度有相关性(P=0.024,r=0.976)。结论 纤维桩弯曲强度与其结构特征相关,纤维/基质比值越高,弯曲强度越大。

Study on flexural strength and microstructure of four different fiber-reinforced composite posts

Objective To test flexural strength of fiber-reinforced composite posts （FRC-posts） and to investigate the relationship between microstrueture and flexural strength. Methods Four types of fiber-reinforced composite posts were tested for this study. They were D. T. Light-Post （ BISCO）, ParePost Taper Lux （ Cohene/Whaledent）, LuxaPost （ DMG）, and domestic fiber post （ Shi De-long）. Five specimens of each experimental group were selected for a three-point bending test and one was processed for SEM evaluation. After three-point bending test,the posts with the highest and the lowest values of flexural strength of each group were additionally processed for SEM analysis. Results The fracture load of the tested posts ranged from 157.40 N to 127.80 N, and the flexural strength from 820.03 MPa to 937.95 MPa. The differences in fiber/matrix ratio ranged from 54.56% to 78.68%. Of the various structural charac- teristics investigated, only the fiber/matrix ratio showed a significant linear correlation to the flexural strength. Conclusions It can be proved that flexural strength of fiber-reinforced composite post is related to its microstructure and the flexural strength increases with the increase of fiber/matrix ratio.