Khosravi Kazem, Mousavinasab Seyed-Mostafa, Samani Mahsa Sahraneshin
Torabinejad Dental Research Center and Department of Restorative Dentistry, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
Dental Material Research Center and Department of Restorative Dentistry, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
Dent Res J (Isfahan). 2015 Mar-Apr;12(2):150-6.
Despite the growing tendency toward tooth-colored restorations in dentistry, polymerization shrinkage and subsequent marginal microleakage remains a problem. The aim of this in vitro study was to compare microleakage between silorane-based and methacrylate-based composite resins at different time intervals and with different restorative techniques.
In this in vitro study, 108 sound extracted human molar teeth were used. Mesial and distal proximal class II boxes with dimensions of 1.5 mm depth and 4 mm width were prepared. The gingival margins of all cavities were 1 mm below the cement enamel junction. The teeth were randomly divided into three groups based on test materials. In the first group, the teeth were restored by a nanocomposite (Filtek Z350XT, 3MESPE) and SE Bond adhesive (Kuraray, Japan), in the second group, the teeth were restored with a silorane-based (Filtek P90, 3MESPE) and Filtek P90 Adhesive (3M ESPE, USA) and in the third group, the teeth were restored with a microhybrid posterior composite resin (Filtek P60, 3MESPE) and SE Bond adhesive (Kuraray, Japan). Half of the proximal cavities in each of these three groups were restored in two horizontal layers and the other half in four horizontal layers. After a period of aging (24-h, 3-month and 6-month) in water and then application of 500 thermal cycles, the teeth were immersed for 24-h in 0.5% fuchsin and evaluated under a stereomicroscope at ×36 magnification to evaluate leakage in gingival margin. Data was statistically analyzed using Kruskal-Wallis and Mann-Whitney U-tests. P ≤ 0.05 was considered as significant.
In Z350XT statistically significant differences were observed in microleakage in comparison of 24-h and 6-month intervals (P = 0.01) that was higher in 6-month. Comparison of microleakage in P90 and P60 composite resins was also statistically significant and was less in P90. Microleakage was not significantly different between P90 and Z350XT at 24-h. However, this difference was significant at 3-month and 6-month intervals. Differences in microleakage of P60 and Z-350XT composite resins were not statistically significant in all intervals (P = 0.38). P90 showed the lowest microleakage during storage in water. Z350XT had microleakage similar to P90 within 24-h, but after 6-month of storage in water, it showed the highest microleakage among all the groups. The number of layers (2 layers vs. 4 layers) did not result in any differences in microleakage scores of the composite resins (P = 0.42).
Water storage times did not result in any significant effect on microleakage of P90 and P60.
尽管牙科领域中使用牙齿颜色修复材料的趋势日益增长，但聚合收缩及随后的边缘微渗漏仍是一个问题。本体外研究的目的是比较在不同时间间隔以及采用不同修复技术时，硅橡胶基复合树脂和甲基丙烯酸酯基复合树脂之间的微渗漏情况。
在本体外研究中，使用了108颗完好拔除的人类磨牙。制备了深度为1.5毫米、宽度为4毫米的近中及远中邻面Ⅱ类洞。所有窝洞的龈缘位于牙骨质釉质界下方1毫米处。根据测试材料将牙齿随机分为三组。第一组，使用纳米复合树脂（Filtek Z350XT，3MESPE）和SE Bond粘结剂（日本可乐丽）进行修复；第二组，使用硅橡胶基材料（Filtek P90，3MESPE）和Filtek P90粘结剂（美国3M ESPE）进行修复；第三组，使用微混合后牙复合树脂（Filtek P60，3MESPE）和SE Bond粘结剂（日本可乐丽）进行修复。这三组中每组近中窝洞的一半分两层水平修复，另一半分四层水平修复。在水中经过一段时间老化（24小时、3个月和6个月），然后进行500次热循环后，将牙齿浸泡在0.5%品红溶液中24小时，并在体视显微镜下以×36放大倍数评估龈缘处的渗漏情况。使用Kruskal-Wallis和Mann-Whitney U检验对数据进行统计学分析。P≤0.05被视为具有显著性。
在Z350XT组中，比较24小时和6个月间隔时的微渗漏情况，差异具有统计学意义（P = 0.01），6个月时的微渗漏更高。P90和P60复合树脂的微渗漏比较也具有统计学意义，且P90的微渗漏较少。24小时时P90和Z350XT之间的微渗漏无显著差异。然而，在3个月和6个月间隔时，这种差异具有显著性。P60和Z - 350XT复合树脂在所有间隔的微渗漏差异均无统计学意义（P = 0.38）。P90在水中储存期间显示出最低的微渗漏。Z350XT在24小时内的微渗漏与P90相似，但在水中储存6个月后，它在所有组中显示出最高的微渗漏。层数（两层与四层）对复合树脂的微渗漏评分没有产生任何差异（P = 0.42）。
储存时间对P90和P60的微渗漏没有产生任何显著影响。
