OBJECTIVES The aim was to assess the influence of polymerization duration, method and resin manipulation techniques on the biaxial flexural strength (BFS) and degree of conversion (DC) of bulk fill resin composites (BFRC). METHODS One hundred and eighty disc specimens were fabricated using MultiCore (MC) and Core-It (CI) bulk fill resin composite. Each material group, specimens were divided into nine subgroups based on curing methods (Light cure for 10 and 20 s; and auto-cure) and mixing techniques (first auto-mix, second automix, and hand mix). BFS was tested with a ball indenter at a crosshead speed of 0.50 mm/min. DC was assessed for MC and CI materials for 10 s and 20 s light cure; and auto cure specimens using Fourier Transform-Infrared Spectroscopy (FTIR). Statistical data comparisons were performed using ANOVA, Bonferroni and Tukey-Kramer tests. RESULTS For MC and CI, BFS was highest in 10 s light cure specimens, however comparable to specimens cured for 20 s (p > 0.05). Auto cure specimens showed lower BFS than light cured samples for both materials (p < 0.05). Hand mixed specimens showed significantly compromised BFS compared to automix technique for MC and CI. DC % was comparable for 10 s and 20 s light cure methods for both materials (p > 0.05), which was higher than DC % of auto cure bulk fill resins (p < 0.05). CI showed higher DC % and BFS compared to MC bulk fill resin composite. CONCLUSION Photo-polymerization duration of 10 and 20 s showed similar outcomes for BFS and DC %; and BFS for auto-mixed resins (MC and CI) was significantly higher than hand mixed resin. BFS and DC was higher in photopolymerized groups as compared to auto-cured resin regardless of the manipulation technique for both materials (MultiCore and Core it).

中文翻译：

---

填充树脂复合材料固化时间和混合技术对双轴抗弯强度和转化率的影响

目的 目的是评估聚合持续时间、方法和树脂操作技术对散装树脂复合材料 (BFRC) 的双轴弯曲强度 (BFS) 和转化度 (DC) 的影响。方法 使用 MultiCore (MC) 和 Core-It (CI) 散装填充树脂复合材料制造了 180 个圆盘试样。每个材料组、试样根据固化方法（光固化 10 秒和 20 秒；以及自动固化）和混合技术（第一次自动混合、第二次自动混合和手动混合）分为九个子组。BFS 用球压头以 0.50 毫米/分钟的十字头速度进行测试。DC 对 MC 和 CI 材料进行了 10 秒和 20 秒的光固化评估；和使用傅里叶变换红外光谱 (FTIR) 自动固化样品。使用方差分析进行统计数据比较，Bonferroni 和 Tukey-Kramer 测试。结果 对于 MC 和 CI，BFS 在 10 秒光固化样品中最高，但与固化 20 秒的样品相当（p > 0.05）。对于两种材料，自动固化样品的 BFS 均低于光固化样品（p < 0.05）。与 MC 和 CI 的自动混合技术相比，手动混合标本的 BFS 显着降低。两种材料的 10 秒和 20 秒光固化方法的 DC % 相当（p > 0.05），高于自动固化本体填充树脂的 DC %（p < 0.05）。与 MC 块状填充树脂复合材料相比，CI 显示出更高的 DC % 和 BFS。结论 10 秒和 20 秒的光聚合持续时间显示 BFS 和 DC % 的结果相似；自动混合树脂（MC 和 CI）的 BFS 显着高于手动混合树脂。