Objective

The inorganic fillers in dental resin composites can enhance their mechanical properties and reduce polymerization shrinkage. When the usage amount of inorganic fillers is closed to maximum filler loading (MFL), the composites will usually achieve optimal performances. This study aims to develop a method that can predict the MFL of dental resin composites for the optimization of filler formulations.

Methods

A method based on discrete element method (DEM) simulations and experiments was firstly developed to predict the MFL of spherical silica particles for single-level and multi-level filling.

Results

The results indicate that the presence of modifier can increase the MFL, and the MFL increment can be exponentially changed with the content of the modifier. Compared with the single-level filling, the addition of secondary fillers is beneficial to increase the MFL, and the increment can be affected by the particle size and size ratio. The prediction results show a good agreement with the experiment results.

Significance

The accuracy of prediction results indicates a great potential of DEM simulations as a numerical experimental method in studying the MFL, and provides an effective method for the optimization of filler formulations.

中文翻译：

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一种基于DEM模拟和实验预测牙科树脂复合材料最大填充量的新方法。

目的

牙科树脂复合材料中的无机填料可增强其机械性能并减少聚合收缩率。当无机填料的使用量接近最大填料载荷（MFL）时，复合材料通常将获得最佳性能。这项研究旨在开发一种可预测牙科树脂复合材料MFL的方法，以优化填料配方。

方法

首次建立了一种基于离散元方法（DEM）的模拟和实验方法，用于预测球形二氧化硅颗粒单级和多级填充的MFL。

结果

结果表明，改性剂的存在可以增加MFL，并且MFL的增加可以随改性剂的含量呈指数变化。与单级填充相比，添加辅助填充剂有利于提高MFL，且增量会受到粒度和尺寸比的影响。预测结果与实验结果吻合良好。

意义

预测结果的准确性表明，DEM模拟作为研究MFL的数值实验方法具有很大的潜力，并为优化填料配方提供了有效的方法。