Grassi Elisa Donaria Aboucauch, de Andrade Guilherme Schmitt, de Carvalho Ana Beatriz Gomes, Gasparro Roberta, Mariniello Mauro, Aliberti Angelo, Ausiello Pietro, Borges Alexandre Luiz Souto
Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (UNESP), 777th Eng. Francisco José Longo Av., São José dos Campos 12245-000, SP, Brazil.
Private Practice, Schmitt Odontologia, Cascavel 85801-031, PR, Brazil.
Dent J (Basel). 2025 Aug 14;13(8):367. doi: 10.3390/dj13080367.
To study the effects of internal and marginal polymerization shrinkage stress and distribution in different resin composite class III dental restorations in relation to the restorative technique using numerical finite element analysis (FEA). A 3D model of a human hemi-maxilla with a sound maxillary central incisor were created. Four class III distal cavities were shaped and differently restored. Four groups of resin composite combinations were analyzed: group C (three increments of conventional composite); group B (two increments of bulk-fill composite); group FC (flowable base + three increments of conventional composite); and group FB (flowable bulk-fill base + two increments of conventional composite). The resulting four models were exported to FEA software for static structural analysis. Polymerization shrinkage was simulated using thermal analogy, and stress distribution was analyzed using the Maximum Principal Stress criterion at the marginal and internal cavity interfaces. Group FC showed the highest stress at the level in the proximal region (9.05 MPa), while group FB showed the lowest (4.48 MPa). FB also exhibited the highest internal dentin stress, indicating potential risks for long-term bond degradation. In the cavo-surface incisal angle, the average peak stress across all groups was 3.76 MPa. At the cervical cavo-surface angle, stress values were 3.3 MPa (C), ~3.36 MPa (B), 3.41 MPa (FC), and 3.27 MPa (FB). Restorative technique did not significantly influence marginal stress distribution in class III composite restorations. However, the bevel area at the cervical margin showed the highest concentration of shrinkage stress.
使用数值有限元分析（FEA）研究不同树脂复合材料III类牙体修复体中内部和边缘聚合收缩应力及其分布与修复技术的关系。创建了一个带有完好上颌中切牙的人类半上颌骨的三维模型。制备了四个III类远中窝洞并进行不同方式的修复。分析了四组树脂复合材料组合：C组（传统复合材料分三层填入）；B组（大块充填复合材料分两层填入）；FC组（流动树脂垫底+传统复合材料分三层填入）；FB组（流动大块充填树脂垫底+传统复合材料分两层填入）。将得到的四个模型导出到FEA软件进行静态结构分析。使用热模拟法模拟聚合收缩，并在边缘和窝洞内部界面处采用最大主应力准则分析应力分布。FC组在近中区域水平显示出最高应力（9.05MPa），而FB组显示出最低应力（4.48MPa）。FB组还表现出最高的牙本质内部应力，表明存在长期粘结降解的潜在风险。在洞缘切角处，所有组的平均峰值应力为3.76MPa。在颈部洞缘角处应力值分别为：C组3.3MPa、B组约3.36MPa、FC组3.41MPa、FB组3.27MPa。修复技术对III类复合树脂修复体的边缘应力分布没有显著影响。然而，颈部边缘的斜面区域显示出收缩应力的最高集中。
