Eskişehir Osmangazi University, Faculty of Dentistry, Department of Restorative Dentistry, Eskişehir, Turkey.
Eskişehir Osmangazi University, Faculty of Dentistry, Department of Restorative Dentistry, Eskişehir, Turkey.
J Mech Behav Biomed Mater. 2018 Jan;77:135-139. doi: 10.1016/j.jmbbm.2017.09.001. Epub 2017 Sep 5.
This study evaluated the effect of simulated chewing forces on the flexural strength of fiber reinforced posts (FRPs). Four different brands of FRPs were selected as main group for the study: RelyX Fiber Post (RX), IceLight (ICE), Unicore Posts (UC), FlouroPost (FP). Ten posts in each main group didn't receive any aging process and tested as baseline (BL), other ten posts were subjected to simulated chewing forces/mechanical aging (MA) as follows: Post spaces were prepared in acrylic with drill. Depth of preparation was adjusted to leave 4-mm coronal part of posts protruding from canals. Coronal parts were incrementally restored with resin-composite (Clearfil Majesty Posterior A2, Kuraray, Osaka, Japan). Prepared samples were subjected to chewing cycles in a chewing simulator (Chewing Simulator CS-4, Mechatronik, Germany). Flexural strengths of all groups were measured with three-point bending test. Data were analyzed by two-way ANOVA and Tukey's test (α = 0.05). After MA, flexural strengths of all posts were significantly decreased when compared with BL for all FRPs tested (p < 0.05). At BL, highest flexural strength values were obtained for ICE. After MA, similar to BL, highest flexural strength values were obtained for ICE. Only RX showed statistically significant difference when compared with ICE (p < 0.05). UC and FP showed similar flexural strength values with ICE (p > 0.05). It may be concluded that chewing forces on post-core systems may reduce the flexural strengths of FRPs.
本研究评估了模拟咀嚼力对纤维增强桩（FRP）弯曲强度的影响。选择四种不同品牌的 FRP 作为主要研究组：RelyX Fiber Post（RX）、IceLight（ICE）、Unicore Posts（UC）、FlouroPost（FP）。每个主要研究组中的 10 个桩不进行任何老化处理，并作为基线（BL）进行测试，其余 10 个桩则承受模拟咀嚼力/机械老化（MA），具体如下：在丙烯酸中用钻头制备桩腔，调整制备深度，使桩的 4mm 冠部从根管中突出。用树脂复合材料（Clearfil Majesty Posterior A2，Kuraray，Osaka，Japan）逐步修复冠部。将制备好的样本放入咀嚼模拟器（Chewing Simulator CS-4，Mechatronik，德国）中进行咀嚼循环。用三点弯曲试验测量所有组别的弯曲强度。数据采用双向方差分析和 Tukey 检验（α=0.05）进行分析。MA 后，与 BL 相比，所有 FRP 的桩弯曲强度均显著降低（p<0.05）。在 BL 时，ICE 的弯曲强度值最高。MA 后，与 BL 相似，ICE 的弯曲强度值最高。与 ICE 相比，仅 RX 表现出统计学差异（p<0.05）。UC 和 FP 与 ICE 的弯曲强度值相似（p>0.05）。可以得出结论，对桩核系统施加咀嚼力可能会降低 FRP 的弯曲强度。
