Abdul Hamid Nor Faharina, Wan Bakar Wan Zaripah, Ariffin Zaihan
Restorative Dentistry Unit, Faculty of Dentistry, Universiti Teknologi MARA, Sungai Buloh Campus, Jalan Hospital, Selangor, Malaysia.
Conservative and Prosthodontics Unit, School of Dental Sciences Health Campus, Universiti Sains, Kubang Kerian Kota Bahru, Kelantan, Malaysia.
Eur J Dent. 2019 Feb;13(1):17-21. doi: 10.1055/s-0039-1688740. Epub 2019 Jun 6.
This study was carried out to assess and compare the marginal gap of conventionally used metal onlays and new resin nanoceramic (RNC) (Lava Ultimate block) onlays.
This is an in vitro study using two extracted sound human mandibular molars. One tooth was prepared to receive the metal onlays and another one for the RNC onlays which were fabricated using the computer-aided design and computer-aided manufacturing (CAD/CAM) technology. Twelve metals and 12 ceramic onlays were fabricated before they were placed at their respective preparation and examined under the Leica stereomicroscope, M125C (Leica Microsystems, Wetzlar, Germany) for a marginal analysis. The gap width was measured at 10 predefined landmarks which included 3 points on the buccal and lingual surfaces each and 2 points each on the mesial and distal surfaces, respectively.
Mann-Whitney post hoc test was used for statistical analysis ( ≤ 0.05).
Overall, the RNC onlays showed significant lower marginal gap with the exception of the landmarks 5 and 6 (on distolingual) and no significant difference at landmark 7 (on midlingual). It was observed that the marginal gap were all within the clinically acceptable limit of 120 μm.
Based on the results obtained, it can be concluded that the RNC CAD/CAM onlays are a promising alternative to the metal onlays.
本研究旨在评估和比较传统使用的金属嵌体与新型树脂纳米陶瓷（RNC）（Lava Ultimate 块体）嵌体的边缘间隙。
这是一项体外研究，使用两颗拔除的健康人下颌磨牙。一颗牙齿预备后用于金属嵌体，另一颗用于 RNC 嵌体，RNC 嵌体采用计算机辅助设计和计算机辅助制造（CAD/CAM）技术制作。制作了 12 个金属嵌体和 12 个陶瓷嵌体，将它们放置在各自的预备牙体上，然后在徕卡体视显微镜 M125C（德国韦茨拉尔徕卡微系统公司）下进行边缘分析。在 10 个预先定义的标志点测量间隙宽度，其中颊面和舌面各 3 个点，近中面和远中面各 2 个点。
采用 Mann-Whitney 事后检验进行统计分析（≤0.05）。
总体而言，除标志点 5 和 6（远舌侧）外，RNC 嵌体的边缘间隙显著更低，在标志点 7（舌侧中部）无显著差异。观察到边缘间隙均在临床上可接受的 120μm 限度内。
根据所得结果，可以得出结论，RNC CAD/CAM 嵌体是金属嵌体的一种有前景的替代物。
