Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
Dent Mater. 2013 Mar;29(3):278-86. doi: 10.1016/j.dental.2012.11.004. Epub 2012 Nov 24.
The aim of this study was to evaluate the void frequency (V(F)) and void volume (V(V)) in different flowable composites using swept-source optical coherence tomography (SS-OCT).
Standard class I cavities were prepared and filled with six different flowable composites: Clearfil Majesty LV (MJ; Kuraray), MI Flow (MW; GC), MI Fil (ML; GC), Beautifil flow plus (BF; Shofu), Palfique Estelite low flow (EL; Tokuyama) and Surefil SDR flow (SF; Dentsply). The restorations were scanned under OCT. The OCT tomograms were analyzed and average V(F) and V(V) per restoration for each composite were calculated. Scanning electron microscope (SEM) was used to observe the structure of each composite. In addition, the flowability of the materials was evaluated measuring the displacement of each material placed up-right on a glass slide. V(F) and V(V) obtained by OCT were also compared to those calculated using micro-computed tomography (micro-CT).
Kruskal-Wallis ANOVA and Mann-Whitney U tests revealed significantly different V(F) and V(V) values (p<0.05) among the composites. Voids ranging from 35 to 785 μm in diameter were detected in OCT tomograms. MJ showed highest V(F) and V(V) values followed by MW, but ML, BF, EL and SF showed no significant difference. Filler volume in composites showed a positive correlation with void formation, but flowability did not show a specific trend. Micro-CT evaluation validated the V(F) and V(V) calculation by OCT, with a significant correlation in void size (p<0.001, r=0.94).
The results of this study indicate the reliability of SS-OCT for real-time void characterization of composite materials and restorations. Void formation in flowable composites is material dependent.
本研究旨在使用扫频源光学相干断层扫描（SS-OCT）评估不同流动型复合材料的空隙频率（V(F)）和空隙体积（V(V)）。
制备标准 I 类窝洞并填充六种不同的流动型复合材料：Clearfil Majesty LV（MJ；Kuraray）、MI Flow（MW；GC）、MI Fil（ML；GC）、Beautifil flow plus（BF；Shofu）、Palfique Estelite low flow（EL；Tokuyama）和Surefil SDR flow（SF；Dentsply）。对修复体进行 OCT 扫描。分析 OCT 断层图像，并计算每个复合材料的每个修复体的平均 V(F)和 V(V)。使用扫描电子显微镜（SEM）观察每种复合材料的结构。此外，通过测量每种材料在玻璃载玻片上垂直放置时的位移来评估材料的流动性。还将 OCT 获得的 V(F)和 V(V)与微计算机断层扫描（micro-CT）计算的值进行比较。
Kruskal-Wallis ANOVA 和 Mann-Whitney U 检验显示复合材料之间的 V(F)和 V(V)值存在显著差异（p<0.05）。OCT 断层图像中检测到直径为 35 至 785μm 的空隙。MJ 表现出最高的 V(F)和 V(V)值，其次是 MW，但 ML、BF、EL 和 SF 之间没有显著差异。复合材料中的填料体积与空隙形成呈正相关，但流动性没有表现出特定的趋势。微 CT 评估验证了 OCT 对 V(F)和 V(V)的计算，空隙大小具有显著相关性（p<0.001，r=0.94）。
本研究结果表明 SS-OCT 可实时用于复合材料和修复体的空隙特征分析。流动型复合材料中的空隙形成是材料依赖性的。
