Nazar Anciya Mohamed, George Liza, Mathew Josey
Department of Conservative Dentistry and Endodontics, Annoor Dental College, Ernakulam, Kerala, India.
J Conserv Dent. 2020 Sep-Oct;23(5):497-504. doi: 10.4103/JCD.JCD_535_20. Epub 2021 Feb 10.
The aim is to evaluate the effect of different layer thickness on the amount of elution of monomers from two high viscosity bulk-fill composites after 24 h and 1 month storage in ethanol using high-performance liquid chromatography (HPLC) analysis.
Forty-eight samples prepared from two high viscosity bulk-fill composite resins; Tetric EvoCeram Bulk Fill and x-tra fil were divided into three groups ( = 8) based on their layer thickness, i.e., Group 1 (2 mm), Group 2 (4 mm), and Group 3 (6 mm) and were then subdivided based on their storage period. The analysis of the eluates was performed using HPLC unit. Statistical analysis was performed using One-way ANOVA, independent sample -test, and paired "t" test at a significance level of 0.05 ( < 0.05).
Increase in layer thickness resulted in increased amount of bisphenol A-glycidyl methacrylate (Bis-GMA) and urethane dimethacrylate (UDMA) elution for both composites, i.e., Group 3 > Group 2 > Group 1 and there was statistically significant difference among all the groups. Tetric EvoCeram Bulk Fill showed a statistically significant increase in amount of Bis-GMA and UDMA elution for all groups compared to x-tra fil. Furthermore, increase in storage period resulted in statistically significant increase in amount of Bis-GMA and UDMA elution for both composites, i.e., Group 1B > Group 1A, Group 2B > Group 2A, and Group 3B > Group 3A. The mean value of UDMA elution was higher when compared to that of Bis-GMA elution for both composites and there was statistically significant difference for all groups.
Within the limitations of this study, it was concluded that increase in layer thickness resulted in increased amount of Bis-GMA and UDMA elution for both Tetric EvoCeram Bulk Fill and x-tra fil.
本研究旨在通过高效液相色谱（HPLC）分析，评估两种高粘度大块充填复合树脂在乙醇中储存24小时和1个月后，不同层厚对单体溶出量的影响。
用两种高粘度大块充填复合树脂——Tetric EvoCeram Bulk Fill和x-tra fil制备48个样本，根据层厚分为三组（每组n = 8），即第1组（2mm）、第2组（4mm）和第3组（6mm），然后再根据储存时间细分。使用HPLC装置对洗脱液进行分析。采用单因素方差分析、独立样本t检验和配对t检验进行统计学分析，显著性水平为0.05（P < 0.05）。
两种复合树脂的层厚增加均导致双酚A - 甲基丙烯酸缩水甘油酯（Bis - GMA）和二甲基丙烯酸聚氨酯（UDMA）溶出量增加，即第3组>第2组>第1组，且所有组间差异具有统计学意义。与x-tra fil相比，Tetric EvoCeram Bulk Fill所有组的Bis - GMA和UDMA溶出量均有统计学意义的增加。此外，储存时间延长导致两种复合树脂的Bis - GMA和UDMA溶出量均有统计学意义的增加，即第1B组>第1A组，第2B组>第2A组，第3B组>第3A组。两种复合树脂的UDMA平均溶出量均高于Bis - GMA，所有组间差异具有统计学意义。
在本研究的局限性范围内，得出结论：Tetric EvoCeram Bulk Fill和x-tra fil的层厚增加均导致Bis - GMA和UDMA溶出量增加。
