Oper Dent. 2020 Sep 1;45(5):537-546. doi: 10.2341/18-160-L.
Some bulk-fill flowable resin composites produce less cuspal deflection than a conventional incrementally filled flowable resin composites.
Objective: This study investigated simulated cuspal deflection and flexural properties of bulk-fill and conventional flowable resin composites.Methods and Materials: Five bulk-fill and six conventional flowable resin composites were evaluated. Aluminium blocks with a mesio-occlusal-distal cavity were prepared and randomly divided into groups for each of the different measurement techniques and were further subdivided according to the type of flowable resin composite. The simulated cuspal deflection caused by the polymerization of resin composite within an aluminium block was measured using a highly accurate submicron digimatic micrometer or a confocal laser scanning microscope (CLSM). In addition, the flexural properties of tested resin composites were measured to investigate the relation between cuspal deflection and flexural properties, and the resin composites were observed using scanning electron microscopy.Results: Simulated cuspal deflection of some bulk-fill flowable resin composites was found to be significantly lower than or similar to those for conventional counterparts, regardless of the measurement method. There were statistically significant differences in flexural properties depending on the material, regardless of the type of flowable resin composite. Pearson correlation analysis did not reveal a statistically significant relationship between flexural properties and cuspal deflection.Conclusion: These results indicate that some bulk-fill flowable resin composites exhibit lower cuspal deflection with the bulk-filling technique than is shown by conventional flowable resin composites using the incremental filling technique. Simulated cuspal deflection can be measured using either a micrometer or CLSM, but this experiment failed to show a significant relationship between cuspal deflection and flexural properties of flowable resin composites.
一些块状填充型可流动树脂复合材料比传统的增量填充型可流动树脂复合材料产生的牙尖位移更小。
目的：本研究旨在研究块状填充型和传统可流动树脂复合材料的模拟牙尖位移和弯曲性能。方法和材料：评估了五种块状填充型和六种传统可流动树脂复合材料。制备了带有近中-颊-远中腔的铝块，并随机将其分为不同测量技术的组，然后根据可流动树脂复合材料的类型进一步细分。使用高精度的数字测微计或共聚焦激光扫描显微镜（CLSM）测量铝块内树脂复合材料聚合引起的模拟牙尖位移。此外，还测量了测试用树脂复合材料的弯曲性能，以研究牙尖位移与弯曲性能之间的关系，并使用扫描电子显微镜观察树脂复合材料。结果：发现一些块状填充型可流动树脂复合材料的模拟牙尖位移明显低于或与传统对应材料相似，无论使用哪种测量方法。弯曲性能因材料而异，与可流动树脂复合材料的类型无关。无论可流动树脂复合材料的类型如何，皮尔逊相关分析均未显示弯曲性能与牙尖位移之间存在统计学显著关系。结论：这些结果表明，与传统的增量填充技术相比，一些块状填充型可流动树脂复合材料在块状填充技术下显示出较低的牙尖位移。可以使用测微计或 CLSM 测量模拟牙尖位移，但该实验未能显示出可流动树脂复合材料的牙尖位移与弯曲性能之间存在显著关系。
