Chiba Ayaka, Hatayama Takashi, Kainose Kimisuke, Nakajima Masatoshi, Pashley David H, Wakabayashi Noriyuki, Tagami Junji
Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University.
Dent Mater J. 2017 Jan 31;36(1):95-102. doi: 10.4012/dmj.2016-160. Epub 2017 Jan 13.
This study aimed to investigate shear stress distributions in resin built-up teeth using resin composites of varying elastic moduli (E), with or without fiber posts. Three-dimensional mathematical models of a root-filled mandibular premolar tooth were constructed. Resin post and cores were built-up with resin composites of three different E: 12,000, 18,000 and 24,000 MPa, with or without fiber posts. Finite element linear analysis was performed to calculate shear stress distributions at bonding interface between resin core and dentin. Regardless of fiber post insertion, the shear stress on the cervical surface of resin core decreased as the E of resin composites increased. Insertion of fiber posts increased the shear stress on the post surface of resin core, with increases in the E of resin composites. In conclusion, using resin core materials with higher E decreased the shear stress at cervical interface between resin core and dentin regardless of fiber post insertion.
本研究旨在调查使用不同弹性模量（E）的树脂复合材料、有无纤维桩时树脂修复牙中的剪切应力分布情况。构建了一个根管充填下颌前磨牙的三维数学模型。树脂桩核用三种不同E值（12000、18000和24000兆帕）的树脂复合材料构建，有无纤维桩。进行有限元线性分析以计算树脂核与牙本质之间粘结界面处的剪切应力分布。无论是否插入纤维桩，随着树脂复合材料E值的增加，树脂核颈部表面的剪切应力降低。插入纤维桩会随着树脂复合材料E值的增加而增加树脂核桩表面的剪切应力。总之，无论是否插入纤维桩，使用具有较高E值的树脂核材料均可降低树脂核与牙本质之间颈部界面处的剪切应力。
