Clinic for Preventive Dentistry, Periodontology and Cariology, University of Zürich, Zürich, Switzerland.
Acta Odontol Scand. 2013 Mar;71(2):317-24. doi: 10.3109/00016357.2012.680905. Epub 2012 Sep 25.
Evaluating the effect of a proximal margin elevation technique on marginal adaptation of ceramic inlays.
Class II MOD-cavities were prepared in 40 human molars and randomly distributed to four groups (n = 10). In group EN (positive control) proximal margins were located in enamel, 1 mm above the cementoenamel junction, while 2 mm below in groups DE-1In, DE-2In and DE. The groups DE-1In, DE-2In and DE simulated subgingival location of the cervical margin. In group DE-1In one 3 mm and in group DE-2In two 1.5 mm composite layers (Tetric) were placed for margin elevation of the proximal cavities using Syntac classic as an adhesive. The proximal cavities of group DE remained untreated and served as a negative control. In all groups, ceramic inlays (Cerec 3D) were adhesively inserted. Replicas were taken before and after thermomechanical loading (1.200.000 cycles, 50/5°C, max. load 49 N). Marginal integrity (tooth-composite, composite-inlay) was evaluated with scanning electron microscopy (200×). Percentage of continuous margin (% of total proximal margin length) was compared between groups before and after cycling using ANOVA and Scheffé post-hoc test.
After thermomechanical loading, no significant differences were observed between the different groups with respect to the interface composite-inlay and tooth-composite with margins in dentin. The interface tooth-composite in enamel of group EN was significantly better compared to group DE-2In, which was not different to the negative control group DE and DE-1In.
Margin elevation technique by placement of a composite filling in the proximal box before insertion of a ceramic inlay results in marginal integrities not different from margins of ceramic inlays placed in dentin.
评估一种近中边缘抬高技术对陶瓷嵌体边缘适应性的影响。
在 40 个人类磨牙上制备 II 类 MOD 腔，并将其随机分为四组（n = 10）。在 EN 组（阳性对照）中，近中边缘位于釉质内，距牙釉质牙骨质界上方 1mm，而在 DE-1In、DE-2In 和 DE 组中，边缘位于牙骨质下方 2mm。DE-1In、DE-2In 和 DE 组模拟龈下边缘位置。在 DE-1In 组中，使用 Syntac classic 作为粘结剂，在近中腔中放置了一层 3mm 的复合层，在 DE-2In 组中放置了两层 1.5mm 的复合层，以抬高近中腔的边缘。DE 组的近中腔未做任何处理，作为阴性对照。所有组均采用粘结法插入陶瓷嵌体（Cerec 3D）。在热机械加载前后（1200000 次循环，50/5°C，最大载荷 49N），取复制件。使用扫描电子显微镜（200×）评估边缘完整性（牙本质-复合层，复合层-嵌体）。使用方差分析和 Scheffé 事后检验比较循环前后各组间总近中边缘长度的连续边缘百分比（% of total proximal margin length）。
热机械加载后，各组间牙本质内复合层-嵌体和牙本质-复合层界面无显著差异。与 DE-2In 组相比，EN 组釉质内牙-复合界面明显更好，而与阴性对照组 DE 和 DE-1In 组无差异。
在插入陶瓷嵌体之前，在近中盒内放置复合填充物以抬高边缘的技术，其边缘完整性与放置在牙本质内的陶瓷嵌体边缘无差异。
