Nova Southeastern University College of Dental Medicine, Fort Lauderdale, FL, USA.
J Prosthodont. 2011 Jun;20(4):267-74. doi: 10.1111/j.1532-849X.2011.00709.x. Epub 2011 Apr 14.
To compare the volumetric misfit between implant restorative platforms of implants and implant frameworks manufactured with two different technologies. One set of implant frameworks was made with a CAD/CAM protocol and a tactile probe; the second protocol consisted of frameworks made with the lost-wax technique and conventional casting technology.
In this laboratory study, an acrylic resin model with five "inter-foraminal" implants was used as the "patient" model. Implant level impressions were made, and 10 definitive master casts were fabricated. The casts were verified using an index made on the patient model. Five cast high palladium noble alloy and five CAD/CAM titanium alloy frameworks were fabricated. The patient's implants and the frameworks' implant restorative platforms were scanned with a tactile probe, and the data were digitized. The digitized implant restorative platforms of the frameworks were fit onto the patient's digitized implants via a software program, in a process called "lofting." This computerized procedure simulated a 1-screw test; the process was performed on both sides. The volumetric misfit between the implant restorative platforms of the frameworks and the patient's implants were measured. A Welch's t-test was used to determine significant differences (p < 0.05) between the misfit of the two technologies. Wilcoxon Signed-Rank tests were used to evaluate differences between the right and left sides.
On average, the volumetric misfit of the CAD/CAM frameworks was 1.8 mm(3) less than the volumetric misfit of the cast alloy frameworks (p < 0.05). The Wilcoxon Signed-Rank tests showed no significant differences between the right and left sides within both systems (p > 0.05).
The scanning technology and computer software program used in this study demonstrated that the CAD/CAM implant frameworks had statistically significantly less volumetric misfit when compared with the cast implant frameworks. There were no significant differences between the right and left 1-screw tests within the same type of frameworks.
比较两种不同技术制造的种植体修复体平台与种植体框架之间的容积不匹配。一套种植体框架采用 CAD/CAM 方案和触觉探头制造；第二个方案由采用失蜡技术和传统铸造技术制造的框架组成。
在这项实验室研究中，使用带有五个“间叉”种植体的丙烯酸树脂模型作为“患者”模型。进行种植体水平印模，并制作 10 个确定性主模型。使用在患者模型上制作的索引验证模型。制作五个铸造高钯贵金属合金和五个 CAD/CAM 钛合金框架。使用触觉探头扫描患者的种植体和框架的种植体修复体平台，并对数据进行数字化。通过软件程序将框架的数字化种植体修复体平台拟合到患者的数字化种植体上，这个过程称为“放样”。这个计算机化的过程模拟了一个 1 颗螺钉测试；在两侧都进行了此过程。测量框架的种植体修复体平台与患者种植体之间的容积不匹配。使用 Welch t 检验确定两种技术之间的不匹配是否存在显著差异（p <0.05）。Wilcoxon 符号秩检验用于评估两种系统中右侧和左侧之间的差异。
平均而言，CAD/CAM 框架的容积不匹配比铸造合金框架的容积不匹配小 1.8mm³（p <0.05）。Wilcoxon 符号秩检验显示两种系统中右侧和左侧之间均无显著差异（p >0.05）。
本研究中使用的扫描技术和计算机软件程序表明，与铸造种植体框架相比，CAD/CAM 种植体框架的容积不匹配具有统计学显著差异。同一类型的框架中，右侧和左侧的 1 颗螺钉测试之间没有显著差异。
