This research aimed to probe the degree of conversion (DoC), porosity and polymerization shrinkage strain (PSS) from three different commercial bulk fill resin composites (BFRCs) with different flowability submitted to two different irradiation protocols. Samples (n = 3) of Tetric N-Ceram (TNF), Opus Bulk Fill (OBF) and Filltek Bulk Fill Flow (FBFF) were studied by FT-IR (for DoC) and micro-CT (for porosity and PSS analysis) after submitted to the following light-cure protocols: P1 (1000 mW/cm² for 20 s) and P2 (3200 mW/cm² for 6 s). All data were statistically treated. The material’s viscosity interfered on its porosity, as well as in the response to the irradiation protocol. Furthermore, data showed that the greater the polymerization shrinkage strain the lower the porosity. On the other hand, the lower the DoC the greater the polymerization shrinkage strain. We conclude that samples of high viscosity composites submitted to extended curing time with lower irradiation showed best physical characteristics for clinical use. The low viscosity FBFF and high power light-cure protocol should be used carefully since it presented the poorest results, which may result in undesirable clinical outcomes.

这项研究的目的是探究三种不同的具有不同流动性的市售填充树脂复合材料（BFRC）的两种转化率（DoC），孔隙率和聚合收缩应变（PSS），这些复合材料分别适用于两种不同的照射方案。 通过FT-IR（用于DoC）和micro-CT（用于孔隙率和PSS分析）研究了Tetric N-Ceram（TNF），Opus批量填充（OBF）和Filltek批量填充流量（FBFF）的样品（n = 3）提交以下光固化方案后：P1（1000 mW / cm ²持续20 s）和P2（3200 mW / cm ²持续6 s）。所有数据均经过统计学处理。材料的粘度会影响其孔隙率以及对辐照方案的响应。此外，数据表明，聚合收缩应变越大，孔隙率越低。另一方面，DoC越低，聚合收缩应变越大。我们得出的结论是，在延长的固化时间和较低的辐照下提交的高粘度复合材料样品显示出最佳的物理特性，可用于临床。低粘度FBFF和高功率光固化方案应谨慎使用，因为其结果最差，可能导致不良的临床结果。