Professor and Head of Department, Department of Prosthodontics and Crown & Bridge, T.P.C.T.'s Terna Dental College, Navi Mumbai, India.
Professor, Department of Prosthodontics and Crown & Bridge, T.P.C.T.'s Terna Dental College, Navi Mumbai, India.
J Prosthet Dent. 2022 May;127(5):716-728.e6. doi: 10.1016/j.prosdent.2021.06.030. Epub 2021 Oct 27.
The marginal and internal adaptation of a fixed dental prosthesis depends on a variety of factors, finish line designs being one of them. A clear consensus as to which finish line design can provide a better marginal and internal adaptation with respect to cobalt-chromium metal alloy copings fabricated by using computer-aided design and computer-aided manufacturing (CAD-CAM) technology is lacking.
The purpose of this systematic review and meta-analysis was to evaluate the effect of different finish line preparations on the marginal and internal adaptation of cobalt-chromium metal alloy copings fabricated by using CAD-CAM technology.
Electronic (PubMed, Cochrane, EBSCOhost, and Google Scholar) and manual searches were conducted for articles published from January 2010 to December 2020 to identify relevant studies evaluating the effect of different finish line preparations (chamfer, deep chamfer, shoulder, rounded shoulder) on the marginal and internal adaptation of cobalt-chromium metal alloy copings fabricated by using CAD-CAM technology.
A total of 573 articles were obtained via electronic search, and 10 articles were obtained through manual search, of which 24 in vitro studies were selected after title, abstract, and full-text screening and were included for both qualitative and quantitative analyses. The marginal adaptation was evaluated under the parameters of marginal gap, absolute marginal discrepancy, and vertical marginal discrepancy, whereas internal adaptation was evaluated under the parameters of internal gap, cervical discrepancy, axial discrepancy, and occlusal discrepancy. The methods of CAD-CAM fabrication (direct metal laser sintering, hard milling, and soft milling) were considered under the subgroup analysis.
An overall better marginal and internal adaptation was observed with shoulder and rounded shoulder finish line designs when CAD-CAM methods were used for coping fabrication. Marginal and internal adaptation in chamfer and deep chamfer finish line designs showed better results with soft milling and direct metal laser sintering methods, whereas shoulder finish line showed better results with hard milling.
固定义齿的边缘和内部适应性取决于多种因素，其中包括边缘线设计。对于使用计算机辅助设计和计算机辅助制造（CAD-CAM）技术制作的钴铬金属合金修复体，哪种边缘线设计可以提供更好的边缘和内部适应性，目前尚未达成明确共识。
本系统评价和荟萃分析的目的是评估不同的边缘线预备对使用 CAD-CAM 技术制作的钴铬金属合金修复体的边缘和内部适应性的影响。
从 2010 年 1 月至 2020 年 12 月，通过电子（PubMed、Cochrane、EBSCOhost 和 Google Scholar）和手动搜索，查找评估不同边缘线预备（斜面、深斜面、肩台、圆肩台）对使用 CAD-CAM 技术制作的钴铬金属合金修复体的边缘和内部适应性影响的相关研究。
通过电子搜索共获得 573 篇文章，通过手动搜索获得 10 篇文章，经过标题、摘要和全文筛选后，共选择了 24 项体外研究进行定性和定量分析。边缘适应性通过边缘间隙、绝对边缘差异和垂直边缘差异等参数进行评估，内部适应性通过内部间隙、颈缘差异、轴向差异和咬合差异等参数进行评估。CAD-CAM 制作方法（直接金属激光烧结、硬铣削和软铣削）被视为亚组分析的一部分。
当使用 CAD-CAM 方法制作修复体时，肩台和圆肩台边缘线设计可获得更好的边缘和内部适应性。在软铣削和直接金属激光烧结方法中，斜面和深斜面边缘线设计显示出更好的边缘和内部适应性，而在硬铣削中，肩台边缘线设计显示出更好的结果。
