Dentist, Oral and Dental Health Center of Güngören, Istanbul, Turkey.
Chief, Professor, Department of Prosthodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey.
J Prosthet Dent. 2018 Feb;119(2):257-262. doi: 10.1016/j.prosdent.2017.03.015. Epub 2017 May 23.
Recently, presintered metal blocks for nonprecious and precious metal implant-supported restorations have gained popularity in computer-aided design and computer-aided manufacturing (CAD-CAM) systems. However, few studies have evaluated the marginal discrepancy of implant-supported restorations made with these new alloy systems.
The purpose of this in vitro study was to compare the milling-sintering method with the lost-wax and milling methods in terms of the marginal fit of implant-supported metal-ceramic restorations.
Thirty implant abutments screwed to implant analogs were embedded into acrylic resin to investigate marginal fit and then divided according to fabrication methods into the following 3 groups (n=10): lost-wax (LW; control group), milling (M), and milling-sintering (MS). Porcelain material was applied to all specimens after completion of the fabrication process. Subsequently, all specimens were cemented to implant abutments for the measurement of marginal discrepancies. Twelve marginal discrepancy measurements were recorded on each implant abutment by using a stereomicroscope. The arithmetic mean of these 12 measurements was considered the mean marginal discrepancy value of each abutment. Data were statistically analyzed by using 1-way ANOVA and Tukey honest significant difference tests (α=.05).
The lowest mean marginal discrepancy values (81 ±2 μm) were observed in the M group, which was significantly different (P<.001) from the other methods. The highest mean marginal discrepancy values (99 ±2 μm) were observed in the MS group.
The results revealed that restorations prepared by the milling-sintering method provided clinically acceptable results (<120 μm); however, this new technique was not found to be as precise as the milling method in terms of marginal fit.
最近，用于非贵金属和贵金属种植体支持修复体的预烧结金属块在计算机辅助设计和计算机辅助制造（CAD-CAM）系统中越来越受欢迎。然而，很少有研究评估使用这些新合金系统制作的种植体支持修复体的边缘不匹配。
本体外研究的目的是比较铣削-烧结法与失蜡和铣削法在种植体支持金属陶瓷修复体边缘适合性方面的差异。
将 30 个种植体基台拧入种植体模拟体中，嵌入丙烯酸树脂中以研究边缘适合性，然后根据制造方法分为以下 3 组（n=10）：失蜡（LW；对照组）、铣削（M）和铣削-烧结（MS）。在完成制造过程后，将瓷材料应用于所有标本。随后，将所有标本粘接到种植体基台上，以测量边缘不匹配。使用立体显微镜在每个种植体基台上记录 12 个边缘不匹配测量值。这 12 个测量值的算术平均值被认为是每个基台的平均边缘不匹配值。使用单因素方差分析和 Tukey 诚实显著差异检验（α=.05）对数据进行统计学分析。
M 组的平均边缘不匹配值最低（81±2μm），与其他方法有显著差异（P<.001）。MS 组的平均边缘不匹配值最高（99±2μm）。
结果表明，通过铣削-烧结法制备的修复体提供了可接受的临床效果（<120μm）；然而，就边缘适合性而言，这种新技术不如铣削法精确。
