Tavangar Seyedeh Maryam, Davalloo Reza Tayefeh, Darabi Farideh, Tajziehchi Gelareh
Department of Restorative Dentistry, School of Dentistry, Guilan University of Medical Sciences, Rasht, Iran.
Department of Restorative Dentistry, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Int J Dent. 2025 Jun 4;2025:7196931. doi: 10.1155/ijod/7196931. eCollection 2025.
This study aimed to compare stress distribution in Class I cavities restored by different techniques according to the stress reducing direct composite (SRDC) concept using finite element analysis (FEA). In this FEA, a model of a three-rooted maxillary molar tooth with a Class I cavity was designed using Mimics 21, Geomagic Design X, and ANSYS software programs. The cavity was restored with a conventional micro-hybrid composite in Group A, bulk-fill composite in Group B, polyethylene fiber beneath the micro-hybrid composite in Group C, and self-cure composite beneath the micro-hybrid composite in Group D. Stress distribution in tooth during resin polymerization and following the application of 600 N load was evaluated in the four groups by FEA. The maximum von Mises stress and total deformation were reported. Almost equal maximum stress values were detected in the enamel close to the dentinoenamel junction and particularly at the marginal ridges in all groups. The maximum stress applied to the hybrid and adhesive layers was greater in Group A, compared with other groups. More uniform stress distribution in the cavity floor was detected in Groups B and C. Stress distribution in the restorative material was less uniform in Group D. Maximum deformation was noted in Group A, followed by Groups C, B, and D. In Class I cavities, application of polyethylene fiber beneath the micro-hybrid composite decreased the maximum stress applied to the adhesive and hybrid layers and total deformation, compared to the use of micro-hybrid composite alone; application of bulk-fill composite and self-cure composite beneath the micro-hybrid composite ranked next. Stress distribution in the cavity floor was more uniform in use of polyethylene fiber beneath the micro-hybrid composite and application of bulk-fill composite.
本研究旨在根据应力降低直接复合树脂（SRDC）概念，使用有限元分析（FEA）比较不同技术修复的I类洞型中的应力分布。在该有限元分析中，使用Mimics 21、Geomagic Design X和ANSYS软件程序设计了一个带有I类洞型的三根上颌磨牙模型。A组用传统微混合复合树脂修复洞型，B组用大块充填复合树脂，C组在微混合复合树脂下方放置聚乙烯纤维，D组在微混合复合树脂下方放置自固化复合树脂。通过有限元分析评估四组在树脂聚合过程中以及施加600 N载荷后的牙齿应力分布。报告了最大von Mises应力和总变形。在所有组中，靠近牙本质-釉质界的釉质中，特别是在边缘嵴处，检测到几乎相等的最大应力值。与其他组相比，A组施加在混合层和粘结层上的最大应力更大。B组和C组在洞底的应力分布更均匀。D组修复材料中的应力分布不太均匀。最大变形出现在A组，其次是C组、B组和D组。在I类洞型中，与单独使用微混合复合树脂相比，在微混合复合树脂下方应用聚乙烯纤维可降低施加在粘结层和混合层上的最大应力以及总变形；在微混合复合树脂下方应用大块充填复合树脂和自固化复合树脂次之。在微混合复合树脂下方使用聚乙烯纤维和应用大块充填复合树脂时，洞底的应力分布更均匀。
