Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Gunduliceva 5, Zagreb, Croatia.
Community Health Center, Zagreb, Croatia.
J Dent. 2021 Aug;111:103708. doi: 10.1016/j.jdent.2021.103708. Epub 2021 May 30.
To investigate the effect of rapid high-intensity light-curing on the marginal integrity of four bulk-fill composites, including two materials specifically designed for high-intensity curing.
Class V cavities were prepared on buccal surfaces of intact human molars with simulated pulpal pressure, filled in a single increment and light-cured using a conventional (10 s @ 1,340 mW/cm) or high-intensity (3 s @ 3,440 mW/cm) protocol. The restorations were subjected to thermo-mechanical loading (TML) comprising 1,200,000 mechanical loading cycles and 3,000 thermocycles. Quantitative margin analysis was performed before and after TML using a scanning electron microscope, and the marginal integrity was expressed as percentage of continuous margin (PCM).
All PCM values measured before TML were statistically similar regardless of the material and curing protocol (p>0.05). A statistically significant effect of the curing protocol (p = 0.021) was identified only after TML for one material. PCM was significantly diminished by TML (p<0.001) for most combinations of material and curing protocol. The PCM values of the sculptable composites after TML were statistically similar regardless of the curing protocol (p>0.05). Compared to these values, significantly lower PCM after TML was identified for the flowable composites cured with the high-intensity protocol (p = 0.001-0.045).
In most cases, high-intensity and conventional curing generally led to similar marginal integrity. Although all of the investigated composites initially performed similarly well, the flowable composites light-cured using the high-intensity protocol showed a significantly inferior marginal integrity compared to the sculptable composites after loading.
Rapid high-intensity light-curing cannot be recommended for flowable bulk-fill composites since it may compromise the tooth-restoration interface.
研究两种专门设计用于高强度固化的材料在内的四种块状填充复合材料的快速高强度光固化对边缘完整性的影响。
在模拟牙髓压力下，在完整的人磨牙颊面制备 V 类洞，用单增量填充并使用常规（10s@1,340mW/cm）或高强度（3s@3,440mW/cm）方案进行光固化。修复体接受热机械加载（TML），包括 120 万次机械加载循环和 3000 次热循环。使用扫描电子显微镜在 TML 前后进行定量边缘分析，并将边缘完整性表示为连续边缘百分比（PCM）。
TML 前测量的所有 PCM 值无论材料和固化方案如何均具有统计学相似性（p>0.05）。只有一种材料在 TML 后才发现固化方案具有统计学意义（p=0.021）。TML 后，大多数材料和固化方案的 PCM 均显著降低（p<0.001）。TML 后可雕刻复合材料的 PCM 值无论固化方案如何均具有统计学相似性（p>0.05）。与这些值相比，TML 后用高强度方案固化的可流动复合材料的 PCM 值明显较低（p=0.001-0.045）。
在大多数情况下，高强度和常规固化通常会导致相似的边缘完整性。尽管所有研究的复合材料最初表现相似，但与可雕刻复合材料相比，用高强度方案固化的可流动复合材料在加载后边缘完整性明显较差。
快速高强度光固化不能推荐用于可流动块状填充复合材料，因为它可能会损害牙齿修复体界面。
