Department of Operative Dentistry, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
Department of Operative Dentistry, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran. ; Biomaterial Research Center, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
J Adv Prosthodont. 2014 Jun;6(3):200-6. doi: 10.4047/jap.2014.6.3.200. Epub 2014 Jun 24.
This in vitro study investigated the fracture resistance of endodontically treated premolars restored using silorane- or methacrylate-based composite along with or without fiber or nano-ionomer base.
Ninety-six intact maxillary premolars were randomly divided into eight groups (n = 12). G1 (negative control) was the intact teeth. In Groups 2-8, root canal treatment with mesio-occlusodistal preparation was performed. G2 (positive control) was kept unrestored. The other groups were restored using composite resin as follows: G3, methacrylate-based composite (Z250); G4, methacrylate composite (Z250) with polyethylene fiber; G5 and G6, silorane-based composite (Filtek P90) without and with the fiber, respectively; G7 and G8, methacrylate- and silorane-based composite with nano-ionomer base, respectively. After aging period and thermocycling for 1000 cycles, fracture strength was tested and fracture patterns were inspected. The results were analyzed using ANOVA and Tukey HSD tests (α=0.05).
Mean fracture resistance for the eight groups (in Newton) were G1: 1200 ± 169(a), G2: 360 ± 93(b), G3: 632 ± 196(c), G4: 692 ± 195(c), G5: 917 ± 159(d), G6: 1013 ± 125(ad), G7: 959 ± 148(d), G8: 947 ± 105(d) (different superscript letters revealed significant difference among groups). Most of the fractures in all the groups were restorable, except Group 3.
Silorane-based composite revealed significantly higher strength of the restored premolars compared to that of methacrylate one. Fiber insertion demonstrated no additional effect on the strength of both composite restorations; however, it increased the prevalence of restorable fracture of methacrylate-based composite restored teeth. Using nano-ionomer base under methacrylate-based composite had a positive effect on fracture resistance and pattern. Only fiber-reinforced silorane composite restoration resulted in a strength similar to that of the intact teeth.
本体外研究调查了使用硅烷或甲基丙烯酸酯基复合材料以及是否使用纤维或纳米离聚物基底修复根管治疗的前磨牙的抗断裂能力。
96 颗完整的上颌前磨牙随机分为 8 组（n = 12）。G1（阴性对照）为完整的牙齿。在第 2-8 组中，进行了近中-远中制备的根管治疗。G2（阳性对照）保持未修复状态。其他组分别用复合树脂修复：G3，甲基丙烯酸酯基复合材料（Z250）；G4，甲基丙烯酸酯复合材料（Z250）加聚乙烯纤维；G5 和 G6，硅烷基复合材料（Filtek P90），分别为无纤维和有纤维；G7 和 G8，甲基丙烯酸酯和硅烷基复合材料分别与纳米离聚物基底。经过老化期和 1000 次热循环后，测试了断裂强度并检查了断裂模式。使用方差分析和 Tukey HSD 检验（α=0.05）对结果进行分析。
八组的平均断裂阻力（以牛顿计）为 G1：1200±169（a），G2：360±93（b），G3：632±196（c），G4：692±195（c），G5：917±159（d），G6：1013±125（ad），G7：959±148（d），G8：947±105（d）（不同的上标字母表示组间有显著差异）。除第 3 组外，所有组的大多数骨折均为可修复性骨折。
与甲基丙烯酸酯基复合材料相比，硅烷基复合材料修复的前磨牙强度明显更高。纤维插入对两种复合材料的强度没有额外的影响；然而，它增加了可修复性骨折的患病率，甲基丙烯酸酯基复合材料修复的牙齿。在甲基丙烯酸酯基复合材料下使用纳米离聚物基底对断裂阻力和模式有积极影响。只有纤维增强的硅烷复合材料修复后，其强度与完整牙齿相似。
