J Adhes Dent. 2024 Oct 14;26:223-230. doi: 10.3290/j.jad.b5759489.
To evaluate interfacial three-dimensional adaptation and internal voids of different flowable materials before and after cyclic fatigue in a simulated deep-margin elevation scenario.
Eighty (n = 80) extracted premolars were selected and two Class II cavities were prepared. The mesial one with cervical margin 1 mm above the cementum-enamel junction (CEJ) and the distal one with cervical margin 1 mm below the CEJ. After performing adhesive procedures, specimens were divided into four groups according to the employed materials for 2 mm horizontal deep-margin relocation: nanohybrid composite (Clearfil ES2, Kuraray); conventional viscosity flowable composite (Tetric Flow, Ivoclar); medium viscosity flowable composite (Majesty ES2 Low Flow, Kuraray); high viscosity flowable composite (Majesty ES2 Super Low Flow, Kuraray). All restorations were finalized by oblique layering with nanohybrid composite (Clearfil ES2, Kuraray). To reveal interfacial and internal gap progression, specimens were scanned with a micro-CT (SkyScan 1172), before and after 500,000 cycles of mechanical chewing simulation (50 N, 1 Hz). Data were imported into Mimics software after smoothing and region growing. Only the 2 mm margin relocation volumes were considered. Obtained masks were analyzed for noise removal and volume calculation. At baseline, interfacial gap progression and internal voids, expressed in mm3, were collected and statistically analyzed with two-way ANOVA (α 0.05) for the variables substrate and restorative materials followed by Tukey post-hoc test. An additional two-way ANOVA test, followed by Tukey post-hoc test, was performed to evaluate variation in interfacial gap progression after mechanical aging.
At baseline, the ANOVA test showed a significant difference for the variable restorative materials (p = 0.01). More specifically, the Tukey post-hoc test revealed that the highly filled medium viscosity composite performed better than the conventional viscosity composite at baseline for the interfacial gap. The internal voids ANOVA test at baseline reported no significant differences for the variable tested. Analysis of variance for internal gap progression after thermocycling showed no differences for both substrate and restorative material employed.
Highly filled medium viscosity composite performed significantly better than the conventional viscosity flowable composite for what concern baseline interfacial gaps. Artificial aging with a chewing simulator and thermocycling did not affect interfacial gap progression on enamel and dentin. The tested restorative materials performed equally after aging.
在模拟深边缘抬升场景中，评估不同流动性材料在循环疲劳前后的界面三维适应性和内部空隙。
选择 80 颗（n=80）提取的前磨牙，并制备两个 II 类洞。近中一个的颈缘位于牙骨质-釉质交界处（CEJ）上方 1 毫米，远中一个的颈缘位于 CEJ 下方 1 毫米。完成粘结程序后，根据用于 2 毫米水平深边缘复位的材料将标本分为四组：纳米复合树脂（Clearfil ES2，Kuraray）；传统粘度流动复合树脂（Tetric Flow，Ivoclar）；中粘度流动复合树脂（Majesty ES2 Low Flow，Kuraray）；高粘度流动复合树脂（Majesty ES2 Super Low Flow，Kuraray）。所有修复体均采用纳米复合树脂（Clearfil ES2，Kuraray）斜分层完成。为了揭示界面和内部间隙的进展，在进行 50 万次机械咀嚼模拟（50 N，1 Hz）之前和之后，使用 micro-CT（SkyScan 1172）对标本进行扫描。数据在平滑和区域生长后导入 Mimics 软件。仅考虑 2 毫米边缘复位体积。获得的掩模经过噪声去除和体积计算分析。在基线时，收集界面间隙进展和内部空隙（以 mm3 表示），并使用双向方差分析（α0.05）对基底和修复材料进行统计分析，然后进行 Tukey 事后检验。进行了另外的双向方差分析测试，然后进行 Tukey 事后检验，以评估机械老化后界面间隙进展的变化。
在基线时，方差分析检验显示修复材料变量存在显著差异（p=0.01）。更具体地说，Tukey 事后检验显示，在基线时，高填充中粘度复合材料在界面间隙方面的表现优于传统粘度复合材料。在基线时，内部空隙方差分析检验报告测试变量无显著差异。热循环后内部间隙进展的方差分析显示，所使用的基底和修复材料均无差异。
在界面间隙方面，高填充中粘度复合材料的性能明显优于传统粘度流动复合材料。咀嚼模拟器和热循环的人工老化对牙釉质和牙本质的界面间隙进展没有影响。老化后，测试的修复材料性能相当。
