Assistant Professor, Department of Prosthodontics, Dental Sciences Research Center, School of Dentistry, Guilan University of Medical Sciences, Rasht, Iran.
Assistant Professor, Department of Orthodontics, Dental Sciences Research Center, School of Dentistry, Guilan University of Medical Sciences, Rasht, Iran.
J Prosthet Dent. 2021 Feb;125(2):325.e1-325.e5. doi: 10.1016/j.prosdent.2020.05.042. Epub 2020 Nov 13.
The digital scanning technique has been introduced as an alternative to the conventional impression technique for the fabrication of fixed restorations. However, adequate information is not available on the efficacy of digital scanning for the fabrication of endocrowns regarding their marginal accuracy.
The purpose of this in vitro study was to compare the marginal gap of endocrowns fabricated by computer-aided design and computer-aided manufacturing (CAD-CAM) technology and digital scanning and conventional impression techniques.
An endodontically treated mandibular molar tooth was prepared to receive an endocrown. The impressions were made by using the conventional impression technique with polyvinyl siloxane material (n=11) and digital scanning by using an intraoral scanner (n=11). Endocrowns were fabricated from monolithic zirconia blocks by using a milling machine. Each restoration was seated on the prepared tooth, and the marginal gap was measured by using a video measuring machine at 8 points under magnification. The mean marginal gap for each restoration and the overall mean marginal gap for each group were calculated. Data were analyzed by using a statistical software program. Marginal gaps were compared with the Mann-Whitney U test (α=.05).
The mean marginal gap was 74 μm for the conventional impression group. A similar mean marginal gap (70 μm) was found for the digital scanning group. No statistically significant difference was found between the groups (P=.375).
The digital scanning technique and the conventional impression technique yielded crowns with comparable marginal adaptation.
数字化扫描技术已被引入作为传统印模技术的替代方法，用于制作固定修复体。然而，关于数字化扫描在制作核冠方面的边缘精度的效果，缺乏足够的信息。
本体外研究的目的是比较计算机辅助设计和计算机辅助制造（CAD-CAM）技术以及数字化扫描和传统印模技术制作核冠的边缘间隙。
对一颗下颌磨牙进行根管治疗后，预备用于接收核冠。使用聚硅氧烷材料的传统印模技术（n=11）和口内扫描仪的数字化扫描技术（n=11）进行印模。通过铣床从整体氧化锆块中制作核冠。将每个修复体放置在预备好的牙齿上，使用视频测量机在放大 8 倍的情况下测量 8 个点的边缘间隙。计算每个修复体的平均边缘间隙和每个组的总体平均边缘间隙。使用统计软件程序进行数据分析。使用曼-惠特尼 U 检验（α=.05）比较边缘间隙。
传统印模组的平均边缘间隙为 74μm。数字化扫描组的平均边缘间隙相似（70μm）。组间无统计学差异（P=.375）。
数字化扫描技术和传统印模技术制作的牙冠具有可比较的边缘适应性。
