Background An occurrence of secondary caries around the indirect restoration margin is reported to remain a leading cause of failures. Objective This study aimed to test the interfacial microleakage of conventional glass-ionomer (CGI), resin-modified glass ionomer (RMGI) and Nano-hybrid composite (CR) restorations at a full veneer margin crown. Methods Ninety human extracted molar teeth were divided into three groups (n = 30). Each group was subdivided into three subgroups (n = 10) according to the extent of the structural defects; The structural defect in G1 had a depth of 1.5 mm, width and length at 2 mm and 1 mm intrusion within the crown cervical margin. The corresponding structural defect dimension values for G2 were 2, 5, 4 and 2 mm with defects extending onto the root structure. Meanwhile, G3: structural deficiency of 2 mm depth, 3 mm width and 3 mm length and with 1.5 mm extension into the prepared teeth. These structural defects in each subgroup were restored with CGI, RMGI and CR. Artificial carious lesion formation was induced at the cervical finish line with a demineralizing solution. The artificial carious lesions were restored as per the group distribution. Subsequently, teeth samples were prepared and cemented with Nickel-chromium full coverage restorations utilizing glass-ionomer luting cement. Teeth samples were thermocycled, isolated with nail varnish, and immersed in 0.1% methylene blue for 24 h. The teeth samples were sectioned longitudinally, dye penetration was evaluated with a stereomicroscope. The data were analyzed with Kruskal–Wallis and Mann–Whitney U tests. Results CGI-G1 recorded the highest micro-leakage score at 1.450; while CR-G3 recorded the least score (0.350). At a cementum-restoration interface, CR-G1 (0.850) documented the lowest micro-leakage; RMGI-G3 had a greater value at 1.700. Conclusions The hybrid CR could be effectively used to restore the restoration of a marginal gap around crown margins.

中文翻译：

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比较不同修复材料修复冠缘边缘间隙的微渗漏

背景 据报道，间接修复边缘周围发生继发龋仍然是失败的主要原因。目的 本研究旨在测试传统玻璃离聚物 (CGI)、树脂改性玻璃离聚物 (RMGI) 和纳米混合复合材料 (CR) 修复体在全贴面边缘牙冠的界面微渗漏。方法 90 颗人类拔除的臼齿分为三组（n = 30）。每组根据结构缺陷的程度分为三个亚组（n = 10）；G1 结构缺损深度为 1.5 mm，宽度和长度为 2 mm，在冠颈缘内侵入 1 mm。G2 的相应结构缺陷尺寸值为 2、5、4 和 2 毫米，缺陷延伸到根部结构。同时，G3：2mm深度的结构缺陷，3 毫米宽和 3 毫米长，并在准备好的牙齿中延伸 1.5 毫米。每个亚组中的这些结构缺陷通过 CGI、RMGI 和 CR 得到修复。用脱矿质溶液在宫颈终点线诱导人工龋损形成。人工龋损按组分布进行修复。随后，使用玻璃离子粘固剂制备牙齿样品并用镍铬全覆盖修复体进行粘接。对牙齿样品进行热循环，用指甲油隔离，并在 0.1% 亚甲蓝中浸泡 24 小时。将牙齿样品纵向切片，用立体显微镜评估染料渗透。使用 Kruskal-Wallis 和 Mann-Whitney U 检验分析数据。结果 CGI-G1 的微漏分数最高，为 1.450；而 CR-G3 的得分最低（0.350）。在牙骨质-修复体界面，CR-G1 (0.850) 记录了最低的微渗漏；RMGI-G3 的值更大，为 1.700。结论混合CR可有效用于修复冠缘边缘间隙的修复。