Dewan Harisha
Department of Prosthetic Dental Sciences, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia.
Biomimetics (Basel). 2023 Aug 27;8(5):394. doi: 10.3390/biomimetics8050394.
Additive manufacturing (three-dimensional (3D) printing) has become a leading manufacturing technique in dentistry due to its various advantages. However, its potential applications for dental ceramics are still being explored. Zirconia, among ceramics, has increasing popularity and applications in dentistry mostly due to its excellent properties. Although subtractive manufacturing (3D milling) is considered the most advanced technology for the fabrication of zirconia restorations, certain disadvantages are associated with it.
A systematic review was piloted to compare the clinical performance of zirconium crowns that were fabricated using three-dimensional (3D) milling and 3D printing. A meta-analysis was performed, and studies published up to November 2022 were identified. The terms searched were "Zirconium crowns", "3D printing", "CAD/CAM" (Computer-Aided Design and Computer-Aided Manufacturing), "Milling", "dental crowns", and "3D milling". The characteristics that were compared were the year in which the study was published, study design, age of the patient, country, the number of crowns, the type of crown fabrication, marginal integrity, caries status, and outcomes. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to structure this systematic review. Out of eleven hundred and fifty titles identified after a primary search, nine articles were included in the quantitative analysis. The research question based on PICO/PECO (Participant, Intervention/exposure, Comparison, and Outcome) was "Do 3D-printed and milled (P) zirconia crowns and FDPs (I) have a better survival rate (O) when conventional prosthesis is also an option (C)"? The data collected were tabulated and compared, and the risk of bias and meta-analysis were later performed. Only nine articles (clinical research) were selected for the study. Since there were no clinical studies on the 3D printing of zirconium crowns, six in vitro studies were considered for the comparison. Zirconium crowns in the milling group had an average minimum follow-up of 6 months.
A moderate risk of bias was found, and survival was significant. A high heterogeneity level was noted among the studies. Marginal integrity, periodontal status, and survival rate were high. Linear regression depicted no statistical correlation between the type of cement used and the survival rate.
It can be concluded that the milled crowns had a higher performance and satisfactory clinical survival.
增材制造（三维（3D）打印）因其诸多优点已成为牙科领域的领先制造技术。然而，其在牙科陶瓷方面的潜在应用仍在探索中。在陶瓷材料中，氧化锆因其优异性能在牙科领域的受欢迎程度和应用日益增加。尽管减材制造（3D铣削）被认为是制造氧化锆修复体最先进的技术，但它也存在一些缺点。
开展一项系统评价，比较采用三维（3D）铣削和3D打印制作的锆冠的临床性能。进行了荟萃分析，并检索了截至2022年11月发表的研究。检索词为“锆冠”“3D打印”“CAD/CAM”（计算机辅助设计和计算机辅助制造）“铣削”“牙冠”和“3D铣削”。比较的特征包括研究发表年份、研究设计、患者年龄、国家、牙冠数量、牙冠制作类型、边缘完整性、龋病状况和结果。采用系统评价和荟萃分析的首选报告项目（PRISMA）指南来构建本系统评价。在初步检索后确定的1150篇文献中，9篇文章纳入定量分析。基于PICO/PECO（参与者、干预/暴露、对照和结果）的研究问题是“当传统修复体也是一种选择时（C），3D打印和铣削（P）的氧化锆冠和固定局部义齿（I）的生存率（O）是否更高”？收集的数据制成表格并进行比较，随后进行偏倚风险评估和荟萃分析。本研究仅选择了9篇文章（临床研究）。由于没有关于锆冠3D打印的临床研究，纳入6篇体外研究进行比较。铣削组锆冠的平均最短随访时间为6个月。
发现存在中度偏倚风险，且生存率具有显著性。研究之间存在高度异质性。边缘完整性、牙周状况和生存率较高。线性回归显示所用粘结剂类型与生存率之间无统计学相关性。
可以得出结论，铣削冠具有更高的性能和令人满意的临床生存率。
