Izadi Alireza, Vafaee Fariborz, Shishehian Arash, Roshanaei Ghodratollah, Fathi Afkari Behzad
Department of Prosthodontic Dentistry, Faculty of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran.
Implant Research Center, Department of Prosthodontics, Faculty of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran.
J Dent Res Dent Clin Dent Prospects. 2018 Fall;12(4):264-271. doi: 10.15171/joddd.2018.041. Epub 2018 Dec 19.
Recently, non-presintered chromium-cobalt (Cr-Co) blocks with the commercial name of Ceramill Sintron were introduced to the market. However, comprehensive studies on the dimensional accuracy and fit of multi-unit frameworks made of these blocks using the coordinate measuring machine (CMM) are lacking. This study aimed to assess and compare the dimensional changes and fit of conventional casting and milled frameworks using Ceramill Sintron. A metal model was designed and scanned and 5-unit frameworks were fabricated using two techniques: (I) the conventional casting method (n=20): the wax model was designed, milled in the CAD/CAM machine, flasked and invested; (II) the milling method using Ceramill Sintron blocks (n=20): the wax patterns of group 1 were used; Ceramill Sintron blocks were milled and sintered. Measurements were made on the original reference model and the fabricated frameworks using the CMM in all the three spatial dimensions, and dimensional changes were recorded in a checklist. Data were analyzed with descriptive statistics, and the two groups were compared using one-way ANOVA and Tukey test (α=0.05). The fabricated frameworks in both groups showed significant dimensional changes in all the three dimensions. Comparison of dimensional changes between the two groups revealed no significant differences (P>0.05) except for transverse changes (arch) that were significantly greater in Ceramill Sintron frameworks (P<0.05). The two manufacturing processes were the same regarding dimensional changes and the magnitude of marginal gaps and both processes resulted in significant dimensional changes in frameworks. Ceramill Sintron frameworks showed significantly greater transverse changes than the conventional frameworks.
最近，一种商品名为Ceramill Sintron的非预烧结铬钴（Cr-Co）块体被推向市场。然而，目前缺乏使用坐标测量机（CMM）对由这些块体制成的多单元框架的尺寸精度和适配性进行全面研究。本研究旨在评估和比较使用Ceramill Sintron的传统铸造框架和铣削框架的尺寸变化和适配性。设计并扫描了一个金属模型，并使用两种技术制作了5单元框架：（I）传统铸造方法（n = 20）：设计蜡模，在CAD/CAM机器中铣削，包埋并装盒；（II）使用Ceramill Sintron块体的铣削方法（n = 20）：使用第1组的蜡型；铣削并烧结Ceramill Sintron块体。在原始参考模型和制作好的框架上使用CMM在所有三个空间维度上进行测量，并将尺寸变化记录在检查表中。数据采用描述性统计进行分析，两组之间的比较采用单因素方差分析和Tukey检验（α = 0.05）。两组制作的框架在所有三个维度上均显示出显著的尺寸变化。两组之间尺寸变化的比较显示，除了横向变化（牙弓）在Ceramill Sintron框架中显著更大（P < 0.05）外，没有显著差异（P > 0.05）。在尺寸变化和边缘间隙大小方面，两种制造工艺相同，并且两种工艺都会导致框架出现显著的尺寸变化。Ceramill Sintron框架的横向变化明显大于传统框架。
