Lassila Lippo V J, Tanner Johanna, Le Bell Anna-Maria, Narva Katja, Vallittu Pekka K
Department of Prosthetic Dentistry and Biomaterials Research, Institute of Dentistry, University of Turku, Turku 20520, Finland.
Dent Mater. 2004 Jan;20(1):29-36. doi: 10.1016/s0109-5641(03)00065-4.
Fiber-reinforced composite (FRC) root canal posts have been introduced to be used instead of metal alloys and ceramics. The aim of this study was to investigate the flexural properties of different types of FRC posts and compare those values with a novel FRC material for dental applications.
Seventeen different FRC posts of various brands (Snowpost, Carbopost, Parapost, C-post, Glassix, Carbonite) and diameters, (1.0-2.1 mm) and a continuous unidirectional E-glass FRC polymerized by light activation to a cylindrical form (everStick, diameter 1.5 mm) as a control material were tested. The posts (n=5) were stored at room's humidity or thermocycled (12.000 x, 5 degrees C/55 degrees C) and stored in water for 2 weeks before testing. A three-point bending test (span=10 mm) was used to measure the flexural strength and modulus of FRC post specimens.
Analysis of ANOVA revealed that thermocycling, brand of material and diameter of specimen had a significant effect (p<0.001) on the fracture load and flexural strength. The highest flexural strength was obtained with the control material (everStick, 1144.9+/-99.9 MPa). There was a linear relationship between fracture load and diameter of posts for both glass fiber and carbon fiber posts. Thermocycling decreased the flexural modulus of the tested specimens by approximately 10%. Strength and fracture load decreased approximately 18% as a result of thermocycling.
Considerable variation can be found in the calculated strength values of the studied post brands. Commercial prefabricated FRC posts showed lower flexural properties than an individually polymerised FRC material.
纤维增强复合材料（FRC）根管桩已被引入以替代金属合金和陶瓷。本研究的目的是研究不同类型FRC桩的弯曲性能，并将这些值与一种新型牙科应用FRC材料进行比较。
测试了17种不同品牌（Snowpost、Carbopost、Parapost、C-post、Glassix、Carbonite）、不同直径（1.0 - 2.1毫米）的FRC桩，以及一种通过光活化聚合成圆柱形的连续单向E玻璃FRC（everStick，直径1.5毫米）作为对照材料。桩（n = 5）在室温湿度下储存或进行热循环（12000次，5摄氏度/55摄氏度），并在测试前在水中储存2周。采用三点弯曲试验（跨度 = 10毫米）测量FRC桩试件的弯曲强度和模量。
方差分析表明，热循环、材料品牌和试件直径对断裂载荷和弯曲强度有显著影响（p < 0.001）。对照材料（everStick，1144.9 ± 99.9兆帕）获得了最高的弯曲强度。玻璃纤维桩和碳纤维桩的断裂载荷与桩直径之间均存在线性关系。热循环使测试试件的弯曲模量降低了约10%。热循环导致强度和断裂载荷降低了约18%。
在所研究的桩品牌的计算强度值中可发现相当大的差异。商业预制FRC桩的弯曲性能低于单独聚合的FRC材料。
