This study compared shrinkage strain, polymerization shrinkage kinetics, and degree of conversion (DC) of a set of resin composites and investigated their influencing factors. Ten commercial resin composites were assessed, and 5 specimens (n = 5) were developed for material and subjected to light curing using light emitting diode light at 650 mW/cm² for 40 s. The laser triangulation method was adopted to assess the shrinkage strain, and Fourier transform infrared spectroscopy was used to measure DC. The shrinkage strain was monitored for 5 min in real time and its data were subjected to differential calculations to get the shrinkage strain rate curve with respect to time, obtaining the maximum shrinkage strain rate (R_max) and gel time. The values of shrinkage strain varied from 1.28% to 2.10%. The R_max values were between 5.17 μm/s and 21.83 μm/s. Gel time values varied from 3.08 s to 4.32 s. The DC yielded values ranging from 53.62% to 87.01%. The values of polymerization shrinkage and DC were dependent on the composition of materials, including the monomer matrix and filler system. Compared to the micro-filler materials, the nano-filler resin composites had higher values of DC. Some resin composites are suitable for clinical applications because of their superior polymerization shrinkage properties and DC.

这项研究比较了一组树脂复合材料的收缩应变，聚合收缩动力学和转化率（DC），并研究了其影响因素。评估了十种市售树脂复合材料，并开发了5个样品（n = 5）作为材料，并使用650 mW / cm ^2的发光二极管光进行了40 s的光固化。采用激光三角测量法评估收缩应变，并使用傅立叶变换红外光谱法测量直流。实时监测收缩应变5分钟，对其数据进行微分计算，得出收缩应变率随时间变化的曲线，得出最大收缩应变率（R _max）和凝胶时间。收缩应变的值在1.28％至2.10％之间变化。R _max值在5.17μm/ s和21.83μm/ s之间。胶凝时间值从3.08 s到4.32 s不等。DC产生的值介于53.62％至87.01％之间。聚合收缩率和DC值取决于材料的组成，包括单体基质和填料体系。与微填料材料相比，纳米填料树脂复合材料具有更高的DC值。一些树脂复合材料因其优异的聚合收缩性能和DC而适合于临床应用。