Tribst João Paulo Mendes, Dal Piva Amanda Maria de Oliveira, Gonçalves Natália In Ês, Borges Alexandre Luiz Souto, Bottino Marco Antonio, Kleverlaan Cornelis Johannes
J Adhes Dent. 2020;22(5):523-530. doi: 10.3290/j.jad.a45182.
To evaluate the effect of composite resin polymerization shrinkage stress on the stress distribution in the implant-supported crown-access hole, and on the bond strength between the ceramic and composite resin.
A 3D model of a ceramic crown, in which the access hole was filled with composite resin (conventional or bulk-fill), was used to evaluate the stress distribution in the access hole using finite element analysis. The contacts were considered bonded and the polymerization shrinkage was simulated based on the coefficient of linear thermal expansion of each resin. The push-out test (1 mm/min, 100 kgf) was performed on perforated lithium disilicate samples filled with conventional or bulk-fill resins to validate the stress data of the bond strength. One-way ANOVA and Tukey's test were used to analyze the bond strength data, with α set at 5%.
Conventional resin showed the worst stress distribution and highest displacement values, von Mises stress, maximum principal strain, maximum principal stress, and maximum shear stress vs the bulk-fill resin. Statistically significantly greater bond strength was observed for bulk-fill (13.40 ± 5.59 MPa) than the conventional resin (8.70 ± 3.02 MPa).
Comparing both materials tested in the present study, the use of bulk-fill composite resin to seal the screw-access hole is suggested to reduce the stress concentration and increase bond strength to the ceramic crown.
评估复合树脂聚合收缩应力对种植体支持冠通道孔内应力分布以及陶瓷与复合树脂之间粘结强度的影响。
采用一个陶瓷冠的三维模型，其中通道孔填充有复合树脂（传统型或大块充填型），通过有限元分析评估通道孔内的应力分布。将接触视为粘结，并根据每种树脂的线性热膨胀系数模拟聚合收缩。对填充有传统型或大块充填型树脂的穿孔二硅酸锂样本进行推出试验（1毫米/分钟，100千克力），以验证粘结强度的应力数据。采用单向方差分析和Tukey检验分析粘结强度数据，α设定为5%。
与大块充填型树脂相比，传统树脂显示出最差的应力分布和最高的位移值、冯·米塞斯应力、最大主应变、最大主应力和最大剪应力。观察到大块充填型树脂（13.40±5.59兆帕）的粘结强度在统计学上显著高于传统树脂（8.70±3.02兆帕）。
比较本研究中测试的两种材料，建议使用大块充填型复合树脂密封螺丝通道孔，以减少应力集中并提高与陶瓷冠的粘结强度。
