Department of Dental Biomaterials, School of Dentistry, Tehran University of Medical Sciences, Iran.
Department of Dental and Biomedical Materials Science, Graduate School of Biomedical Sciences, Nagasaki University, Japan.
Polim Med. 2022 Jan-Jun;52(1):13-18. doi: 10.17219/pim/151857.
Resin composites have various applications. At the same time, they have some drawbacks, such as polymerization shrinkage. Conventional composites are polymerized in 2-mm thick layers. However, in posterior restoration, the 2-mm depth of cure is not satisfactory. To find a solution, resin composites have been vastly improved in terms of fillers, matrix and initiators.
To evaluate polymerization properties and physical characteristics of fiber-reinforced composites and compare them with bulk-fill composites that are designed for large posterior restorations.
Samples were prepared from each resin composite. The 3-point bending test was performed to evaluate the flexural strength of all composites. The depth of cure of the composite from 1 mm to 4 mm of depth was analyzed using Vickers hardness test (VHN). To analyze the degree of conversion, Fourier-transform infrared spectroscopy (FTIR) of the top and bottom surfaces of the samples with 4-mm thickness was calculated. The data were analyzed using one-way analysis of variance (ANOVA) test followed by post hoc test (95% confidence interval (95% CI)).
The Filtek showed the highest flexural strength followed by everX and X-tra fil. At 1-mm depth, X-tra fil had the highest and Gradia had the lowest microhardness. At the 4-mm depth, the microhardness trend was as follows: everX > Filtek > X-tra fil > Gradia > Beautifil. The everX composite had the lowest reduction of the degree of conversion at 4-mm thickness, which showed a significant difference in comparison with Filtek, Gradia and X-tra fil composites.
Based on the results of our study, it can be concluded that the fiber-reinforced composite everX showed more favorable results regarding polymerization properties, such as the degree of conversion and the depth of cure. However, the flexural strength results in Filtek were better than those in everX.
树脂复合材料有多种应用。同时，它们也有一些缺点，如聚合收缩。传统复合材料以 2 毫米厚的层聚合。然而，在后牙修复中，2 毫米的固化深度并不令人满意。为了解决这个问题，树脂复合材料在填料、基质和引发剂方面都有了很大的改进。
评估纤维增强复合材料的聚合性能和物理特性，并将其与旨在用于大体积后牙修复的块状充填复合材料进行比较。
从每种树脂复合材料中制备样本。通过三点弯曲试验评估所有复合材料的弯曲强度。使用维氏硬度试验（VHN）分析复合材料从 1 毫米到 4 毫米深度的固化深度。为了分析转化率，计算了 4 毫米厚样品的顶部和底部表面的傅里叶变换红外光谱（FTIR）。使用单因素方差分析（ANOVA）检验后进行事后检验（95%置信区间（95%CI））对数据进行分析。
Filtek 表现出最高的弯曲强度，其次是 everX 和 X-tra fil。在 1 毫米深度处，X-tra fil 的硬度最高，Gradia 的硬度最低。在 4 毫米深度处，硬度趋势如下：everX > Filtek > X-tra fil > Gradia > Beautifil。everX 复合材料在 4 毫米厚度时的转化率降低最低，与 Filtek、Gradia 和 X-tra fil 复合材料相比，差异有统计学意义。
根据我们的研究结果，可以得出结论，纤维增强复合材料 everX 在聚合性能方面表现出更有利的结果，如转化率和固化深度。然而，Filtek 的弯曲强度结果优于 everX。
