Postgraduate student, Postgraduate Program in Dental Science, Prosthodontics Units, Federal University of Santa Maria (UFSM), Santa Maria, Brazil.
Adjunct Professor, Department of Conservative Dentistry, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.
J Prosthet Dent. 2022 Dec;128(6):1190-1200. doi: 10.1016/j.prosdent.2021.02.031. Epub 2021 Apr 15.
Whether procedures performed before the cementation of computer-aided design and computer-aided manufacturing (CAD-CAM) glass-ceramic restorations, including milling, fitting adjustment, and hydrofluoric acid etching introduce defects on the ceramic surface that affect the mechanical and surface properties is unclear.
A systematic review and meta-analysis were conducted to assess the effect of milling, fitting adjustments, and hydrofluoric acid etching (HF) on the flexural strength and roughness (Ra) of CAD-CAM glass-ceramics.
Literature searches were performed up to June 2020 in the PubMed/MEDLINE, Web of Science, and Scopus databases, with no publication year or language limits. The focused question was "Do milling, fitting adjustments, and hydrofluoric acid etching affect the flexural strength and roughness of CAD-CAM glass-ceramics?" For the meta-analysis, flexural strength and Ra data on milling, fitting adjustment, and HF etching versus control (polishing) were analyzed globally. A subgroup analysis assessed the effect of etching parameters (HF concentration and time) on the flexural strength and roughness of CAD-CAM glass-ceramics with different microstructures. Comparisons were performed with random-effect models at 5% significance.
Fourteen studies from 2764 potentially relevant records were included in the qualitative syntheses, and 12 in the meta-analysis. Milling and fitting adjustments increased roughness and reduced the flexural strength of CAD-CAM glass-ceramics. The effect of HF etching was dependent on the glass-ceramic microstructure, HF concentration, and etching time. For feldspathic- and leucite-reinforced ceramics, HF 5% applied for between 30 and 120 seconds increased roughness without affecting flexural strength. For lithium disilicate glass-ceramics, HF concentrations greater than 4.9% used for 20 seconds or more reduced the strength without affecting the surface roughness.
The flexural strength of CAD-CAM glass-ceramic is reduced by grinding procedures such as milling and fitting adjustment. Ceramic microstructure, HF concentration, and etching time determined the effect of hydrofluoric acid etching on the flexural strength and surface roughness of glass-ceramic materials.
在使用计算机辅助设计和计算机辅助制造（CAD-CAM）玻璃陶瓷修复体之前进行的操作，包括铣削、拟合调整和氢氟酸蚀刻，是否会在陶瓷表面产生影响机械和表面性能的缺陷，目前尚不清楚。
进行系统评价和荟萃分析，以评估铣削、拟合调整和氢氟酸蚀刻（HF）对 CAD-CAM 玻璃陶瓷的弯曲强度和粗糙度（Ra）的影响。
文献检索截至 2020 年 6 月，在 PubMed/MEDLINE、Web of Science 和 Scopus 数据库中进行，无出版年份或语言限制。重点问题是“铣削、拟合调整和氢氟酸蚀刻是否会影响 CAD-CAM 玻璃陶瓷的弯曲强度和粗糙度？”对于荟萃分析，全球分析了铣削、拟合调整和 HF 蚀刻与对照（抛光）相比的 CAD-CAM 玻璃陶瓷的弯曲强度和 Ra 数据。亚组分析评估了蚀刻参数（HF 浓度和时间）对具有不同微观结构的 CAD-CAM 玻璃陶瓷的弯曲强度和粗糙度的影响。在 5%的显著性水平下进行随机效应模型比较。
从 2764 篇潜在相关记录中筛选出 14 项研究进行定性综合分析，12 项研究进行荟萃分析。铣削和拟合调整会增加粗糙度并降低 CAD-CAM 玻璃陶瓷的弯曲强度。HF 蚀刻的效果取决于玻璃陶瓷的微观结构、HF 浓度和蚀刻时间。对于长石增强和白榴石增强陶瓷，HF 5%应用 30-120 秒可增加粗糙度而不影响弯曲强度。对于锂硅玻璃陶瓷，HF 浓度大于 4.9%，应用 20 秒或更长时间会降低强度而不影响表面粗糙度。
CAD-CAM 玻璃陶瓷的弯曲强度会因铣削和拟合调整等加工工艺而降低。陶瓷微观结构、HF 浓度和蚀刻时间决定了氢氟酸蚀刻对玻璃陶瓷材料弯曲强度和表面粗糙度的影响。
