Materials Science Unit, Division of Oral Biosciences, Dublin Dental University Hospital, Trinity College Dublin, Lincoln Place, Dublin 2, Ireland.
Dent Mater. 2012 Jul;28(7):769-76. doi: 10.1016/j.dental.2012.04.003. Epub 2012 May 3.
The aim was to determine the magnitude of ceramic resin-strengthening with resin-based materials with varying flexural moduli using a regression technique to assess the theoretical strengthening at a 'zero' resin-coating thickness. The hypothesis tested was that experimentally, increasing resin flexural modulus results in increased resin-strengthening observed at a theoretical 'zero' resin-coating thickness.
Vitadur Alpha dentin porcelain disk (n=250) were condensed, fired, alumina particle air abraded and randomly assigned into ten groups. Groups were resin-coated at 50, 100 and 150μm with Venus Flow, Rely-X Veneer and Clearfil AP-X before biaxial flexure testing at 24h and the stress at failure calculated using a multilayer analysis. An analytical methodological approach was undertaken to predict the biaxial flexure stresses under boundary conditions that reflected the experimental test and a finite element model was used to verify the analytical prediction.
The magnitude of resin-reinforcement was significantly influenced by resin-coating type (P<0.001) and resin-coating thickness (P=0.013), however, a significant interaction was observed between resin-coating type and thickness (P=0.048). Linear regression identified a 17, 38 and 47% biaxial flexure strength contribution when Venus Flow, Rely-X Veneer and Clearfil AP-X were used, respectively. The finite element model determined the maximum principal stress was within 3.3% of the predicted analytical solution.
Experimentally, the flexural modulus and thickness of resin-based material used to cement DBC or PLV restorations have a significant impact on the magnitude of resin-strengthening observed. However, for resin-based materials with different flexural moduli the variability in the relationships between thickness and observed increases in biaxial flexure strength of the ceramic requires careful characterization to optimize clinical performance.
本研究旨在使用回归技术确定不同弯曲弹性模量的树脂基材料对陶瓷的增强效果，并评估在“零”树脂涂层厚度下的理论增强效果。本研究假设，随着树脂弯曲弹性模量的增加，在理论“零”树脂涂层厚度下观察到的树脂增强效果也会增加。
将 Vitadur Alpha 牙本质瓷圆盘（n=250）压实、烧制、氧化铝颗粒空气喷砂后，随机分为 10 组。使用 Venus Flow、Rely-X Veneer 和 Clearfil AP-X 将每组分别涂布 50、100 和 150μm 的树脂涂层，然后在 24 小时后进行双轴弯曲测试，并使用多层分析计算失效时的应力。采用分析方法预测在反映实验测试条件下的双轴弯曲应力，并使用有限元模型验证分析预测。
树脂增强的程度显著受树脂涂层类型（P<0.001）和树脂涂层厚度（P=0.013）的影响，但树脂涂层类型和厚度之间存在显著的相互作用（P=0.048）。线性回归确定，当使用 Venus Flow、Rely-X Veneer 和 Clearfil AP-X 时，双轴弯曲强度的贡献分别为 17%、38%和 47%。有限元模型确定最大主应力与预测的分析解相差在 3.3%以内。
实验表明，用于粘结 DBC 或 PLV 修复体的树脂基材料的弯曲弹性模量和厚度对观察到的树脂增强效果有显著影响。然而，对于具有不同弯曲弹性模量的树脂基材料，陶瓷的双轴弯曲强度与厚度之间的关系存在较大的可变性，需要仔细表征以优化临床性能。
