摘要
目的 评价不同Ⅱ类复合洞型对银汞合金和复合树脂修复体产生应力的影响。方法在下颌第一磨牙设计 5种近中邻面Ⅱ类复合洞型 ,分别用银汞合金和复合树脂充填 ,采用三维有限元法对充填体承受垂直和侧向力后所产生的应力分别进行计算分析。结果 5种Ⅱ类洞型受到 1 0 0N垂直、侧向作用力后 ,在传统和改良洞型中 ,除银汞合金产生的压应力和受侧向力时的切应力传统洞型比改良洞型小外 ,其余的应力值均是传统洞型比改良洞型大。在有固位沟狭孔、无固位沟狭孔和碟型 3种洞型中 ,复合树脂修复体产生的各种应力均明显小于银汞合金者 ;2种狭孔和碟型洞型产生的应力值均比传统和改良洞型小者。结论 银汞合金充填洞型设计为有固位沟狭孔洞型较好 ;
Objective To assess effects of different class II cavities on stresses of amalgam and composite resin restoration. Methods Five kinds of class II MO cavities were prepared on the first molars of mandibles. The cavities were filled by amalgam and composite resin, respectively. The stresses were analyzed by using three-dimensional finite element method, after vertical and lateral pressures were loaded on the teeth. Results The stresses were greater in traditional cavities than those in reformed cavities when 100 N vertical and lateral pressures were loaded on the teeth. But the pressing stress and shearing stress in cavities filled by amalgam were smaller in traditional cavities than those in reformed cavities. The stresses were smaller in cavities filled by resin than those in cavities filled by amalgam significantly, when the cavities were designed with slot retention groove, without slot retention groove and as plate form. The stresses were smaller in two kinds of slot and plate cavities than those in traditional and reformed cavities. Conclusion It is better to design cavity with slot retention groove for amalgam restoration and to design cavity without slot retention groove for composite resin restoration.
出处
《中华口腔医学杂志》
CAS
CSCD
北大核心
2002年第6期446-448,共3页
Chinese Journal of Stomatology
