Department of Prosthodontics, Jordan University of Science & Technology, Irbid, Jordan.
Private practice, Amman, Jordan.
J Prosthodont. 2022 Oct;31(8):e67-e86. doi: 10.1111/jopr.13553. Epub 2022 Jun 29.
The purpose of this systematic review and meta-analysis was to evaluate the effect of using additive manufacturing (AM) for dental ceramic fabrication in comparison with subtractive manufacturing (SM), and to evaluate the effect of the type of AM technology on dental ceramic fabrication.
A search was conducted electronically in MEDLINE (via PubMed), EBSCOhost, Scopus, and Cochran Library databases, and also by other methods (table of contents screening, backward and forward citations, and grey literature search) up to February 12, 2022, to identify records evaluating additive manufacturing of ceramics for dental purposes in comparison with subtractive manufacturing. A minimum of 2 review authors conducted tstudy selection, quality assessment, and data extraction. Quality assessment was performed with Joanna Briggs Institute tool, and the quantitative synthesis was performed with the Comprehensive Meta-Analysis program (CMA, Biostat Inc). Hedges's g for effect size was calculated, with 0.2 as small, 0.5 as medium, and 0.8 as large. Heterogeneity was assessed with I and prediction interval (PI) statistics. Publication bias was investigated with funnel plots and grey literature search. Certainty of evidence was assessed with the Grading of Recommendations: Assessment, Development, and Evaluation (GRADE) tool.
A total of 28 studies were included for the qualitative and quantitative synthesis; 11 in vitro studies on accuracy, 1 in vivo study on color, and 16 in vitro studies on physical and mechanical properties. Meta-analysis showed overall higher accuracy for SM compared with AM, with medium effect size (0.679, CI: 0.173 to 1.185, p = 0.009) and also for marginal (g = 1.05, CI: 0.344 to 1.760, p = 0.004), occlusal (g = 2.24, CI: 0.718 to 3.766, p = 0.004), and total (g = 4.544, CI: -0.234 to 9.323, p = 0.062) with large effect size; whereas AM had higher accuracy than SM with small effect size for the external (g = -0.238, CI: -1.215 to 0.739), p = 0.633), and internal (g = -0.403, CI: -1.273 to 0.467, p = 0.364) surfaces. For technology, self-glazed zirconia protocol had the smallest effect size (g = -0.049, CI: -0.878 to 0.78, p = 0.907), followed by stereolithography (g = 0.305, CI: -0.289 to 0.9, p = 0.314), and digital light processing (g = 1.819, CI: 0.662 to 2.976, p = 0.002) technologies. Flexural strength was higher for ceramics made by SM in comparison to AM with large effect size (g = -2.868, CI: -4.371 to -1.365, p < 0.001). Only 1 study reported on color, favoring ceramics made through combined AM and SM.
Subtractive manufacturing had better overall accuracy, particularly for the marginal and occlusal areas, higher flexural strength, and more favorable hardness, fracture toughness, porosity, fatigue, and volumetric shrinkage; whereas AM had more favorable elastic modulus and wettability. Both methods had favorable biocompatibility. All studies on accuracy and mechanical properties were in vitro, with high heterogeneity and low to very low certainty of evidence. There is a lack of studies on color match and esthetics.
本系统评价和荟萃分析旨在评估在牙科陶瓷制作中使用增材制造（AM）与减材制造（SM）的效果，并评估 AM 技术类型对牙科陶瓷制作的影响。
通过 MEDLINE（通过 PubMed）、EBSCOhost、Scopus 和 Cochrane 图书馆数据库以及其他方法（目录筛选、回溯和前向引文以及灰色文献搜索），检索截至 2022 年 2 月 12 日评估用于牙科目的的陶瓷添加剂制造与减法制造的记录。至少有 2 位综述作者进行了 t 研究选择、质量评估和数据提取。使用 Joanna Briggs Institute 工具进行质量评估，使用 Comprehensive Meta-Analysis 程序（CMA，Biostat Inc）进行定量合成。计算效应大小的 Hedges'g，0.2 为小，0.5 为中，0.8 为大。使用 I 和预测区间（PI）统计评估异质性。使用漏斗图和灰色文献搜索调查发表偏倚。使用 Grading of Recommendations：Assessment，Development，and Evaluation（GRADE）工具评估证据的确定性。
共有 28 项研究纳入定性和定量综合分析；11 项关于准确性的体外研究、1 项关于颜色的体内研究和 16 项关于物理和机械性能的体外研究。荟萃分析显示，与 AM 相比，SM 的总体准确性更高，具有中等效应大小（0.679，CI：0.173 至 1.185，p = 0.009）和边缘（g = 1.05，CI：0.344 至 1.760，p = 0.004）、咬合（g = 2.24，CI：0.718 至 3.766，p = 0.004）和总（g = 4.544，CI：-0.234 至 9.323，p = 0.062）的大效应大小；而 AM 对于外部（g = -0.238，CI：-1.215 至 0.739，p = 0.633）和内部（g = -0.403，CI：-1.273 至 0.467，p = 0.364）表面，AM 的准确性高于 SM，具有小效应大小。对于技术，自上釉氧化锆协议的效应大小最小（g = -0.049，CI：-0.878 至 0.78，p = 0.907），其次是立体光刻术（g = 0.305，CI：-0.289 至 0.9，p = 0.314）和数字光处理（g = 1.819，CI：0.662 至 2.976，p = 0.002）技术。与 AM 相比，SM 制造的陶瓷的抗弯强度更高，具有大效应大小（g = -2.868，CI：-4.371 至 -1.365，p < 0.001）。只有 1 项研究报告了颜色，有利于通过组合 AM 和 SM 制造的陶瓷。
减材制造具有更好的整体准确性，特别是边缘和咬合区域，更高的抗弯强度，更有利的硬度、断裂韧性、孔隙率、疲劳和体积收缩；而 AM 具有更有利的弹性模量和润湿性。两种方法都具有良好的生物相容性。所有关于准确性和机械性能的研究都是体外研究，具有高度异质性和低至非常低的证据确定性。缺乏关于颜色匹配和美观的研究。
