Farah Ra'fat I, Alresheedi Bandar
Department of Prosthetic Dental Sciences, College of Dentistry, Qassim University, P.O. Box: 6700, Al-Mulaydah, 51452, Qassim, Saudi Arabia.
Clin Oral Investig. 2023 Jan;27(1):263-271. doi: 10.1007/s00784-022-04720-6. Epub 2022 Sep 14.
The purpose of this in vitro study was to assess and compare the marginal and internal fit of machine-milled crowns designed using three different CAD software programs.
Digital impressions of the master zirconia casts containing the prepared molar were obtained using an intraoral scanner. The obtained standard tessellation language (STL) files were imported into three CAD software programs (Multi-CAD, Blue-Sky CAD, and InLab), and crown designs were generated. Crown design digital STL files were used to mill crowns with a five-axis dental milling machine. The internal and marginal fits of the fabricated crowns over the master-prepared tooth were assessed using the triple-scan protocol and digital analysis techniques. The 3D marginal and internal fit values of the fabricated crowns from the designs generated by the three CAD programs were evaluated and statistically compared using one-way analysis of variance (ANOVA) and post hoc Tukey's tests (α = 0.05).
There were no significant differences in the internal fit of the crowns designed by the three CAD programs (p > 0.05). However, there were significant differences in the mean marginal fit (p = 0.009) of the crowns. The marginal fit values for the InLab-designed crowns were significantly better than those for Multi-CAD (p = 0.03) and Blue-Sky CAD (p = 0.012) groups.
All three CAD programs can design clinically acceptable crowns in terms of internal and marginal fit. InLab crowns outperformed the Multi-CAD and Blue-Sky CAD programs in terms of marginal fit.
It is critical to test the ability of newly released CAD programs to design acceptable virtual crowns that can be transformed into actual crowns with optimal marginal and internal fit to existing clinical tooth preparations/conditions to ensure the high technical quality and long-term success of fabricated crowns.
本体外研究的目的是评估和比较使用三种不同计算机辅助设计（CAD）软件程序设计的机械加工全冠的边缘适合性和内部适合性。
使用口腔内扫描仪获取含有制备好的磨牙的氧化锆主模型的数字印模。将获得的标准镶嵌语言（STL）文件导入三种CAD软件程序（Multi-CAD、Blue-Sky CAD和InLab），并生成全冠设计。全冠设计数字STL文件用于通过五轴牙科铣床加工全冠。使用三重扫描方案和数字分析技术评估在主制备牙上制作的全冠的内部和边缘适合性。对由三个CAD程序生成的设计所制作的全冠的三维边缘和内部适合性值进行评估，并使用单因素方差分析（ANOVA）和事后Tukey检验（α = 0.05）进行统计学比较。
三个CAD程序设计的全冠在内部适合性方面无显著差异（p > 0.05）。然而，全冠的平均边缘适合性存在显著差异（p = 0.009）。InLab设计的全冠的边缘适合性值显著优于Multi-CAD组（p = 0.03）和Blue-Sky CAD组（p = 0.012）。
就内部和边缘适合性而言，所有三个CAD程序都可以设计出临床上可接受的全冠。InLab全冠在边缘适合性方面优于Multi-CAD和Blue-Sky CAD程序。
测试新发布的CAD程序设计可接受的虚拟全冠的能力至关重要，这些虚拟全冠能够转化为具有与现有临床牙齿制备/情况最佳边缘和内部适合性的实际全冠，以确保制作的全冠具有高技术质量和长期成功。
