Department of Prosthetic Dentistry, Postgraduate Dental Education Center, Public Dental Health Service, Orebro, Sweden.
Clin Implant Dent Relat Res. 2010 Jun 1;12(2):81-90. doi: 10.1111/j.1708-8208.2008.00131.x. Epub 2008 Dec 3.
New computer numeric controlled (CNC)-milled frameworks for implant-supported prostheses have been introduced. However, no data are available on the precision of fit of these new frameworks.
The purpose of this study is to evaluate the precision of fit of a new CNC-milled framework technique (I-Bridge, Biomain AB, Helsingborg, Sweden) using Brånemark System (Nobel Biocare AB, Göteborg, Sweden) and NobelReplace (Nobel Biocare AB) system implants.
Ten test frameworks were fabricated for one master model for each implant system. Five additional frameworks were fabricated for five different models simulating clinical cases as controls (Brånemark System). The distortion of implant center point positions was measured in x-, y-, and z-axes and in three dimensions by using a contact-type coordinate measuring machine and a computer program developed specifically for this purpose. Mann-Whitney U-test was used to compare differences of distortion within and between the groups.
The maximal distortion in arch width (x-axis) and curvature (y-axis) was within 71 and 55 microm for all frameworks, respectively. The mean distortion in absolute figures in x-, y-, z-axes and three dimensions was for "clinical control" frameworks 23, 26, 4, and 34 microm as compared with less than 12, 12, 2, and 17 microm for Brånemark and NobelReplace frameworks, respectively. Control frameworks showed significantly (p < .05) greater mean and range of distortions in x- and y-axes and in three dimensions compared with test frameworks.
All measured frameworks presented signs of misfit, indicating that no framework had a "passive fit." Frameworks produced in a more routine clinical environment seem to present greater levels of distortion as compared with frameworks produced in a strict test situation. However, all measured frameworks presented levels of precision of fit within limits considered to be clinically acceptable in earlier studies of frameworks placed on abutments.
新型计算机数控（CNC）铣削的种植体支持修复体基台已经问世。然而，目前尚无关于这些新型基台的适配精度的相关数据。
本研究旨在评估新型 CNC 铣削基台技术（I-Bridge，Bomain AB，赫尔辛堡，瑞典）的适配精度，采用 Brånemark 系统（Nobel Biocare AB，哥德堡，瑞典）和 NobelReplace（Nobel Biocare AB）系统种植体。
为每个种植体系统的一个母模制造了 10 个测试基台。另外制造了 5 个基台，用于模拟临床病例的 5 个不同模型作为对照（Brånemark 系统）。使用接触式坐标测量机和专门为此目的开发的计算机程序，在 x、y 和 z 轴以及三维方向上测量种植体中心点位置的变形。采用 Mann-Whitney U 检验比较组内和组间变形的差异。
所有基台的弓宽（x 轴）和曲率（y 轴）的最大变形分别为 71μm 和 55μm。“临床对照”基台的 x、y、z 轴和三维方向上的平均绝对变形分别为 23μm、26μm、4μm 和 34μm，而 Brånemark 和 NobelReplace 基台的平均变形分别小于 12μm、12μm、2μm 和 17μm。与测试基台相比，对照组基台在 x 轴和 y 轴以及三维方向上的平均变形和变形范围均显著（p <.05）增大。
所有测量的基台均显示出失配迹象，表明没有基台具有“被动适配”。在更常规的临床环境中制造的基台与在严格的测试环境中制造的基台相比，似乎呈现出更大的变形水平。然而，所有测量的基台的适配精度均在早期基台放置在基台上的研究中认为可接受的临床范围内。
