Neumeister André, Schulz Linda, Glodecki Christoph
Int J Comput Dent. 2017;20(1):35-51.
This article describes the computer-aided design/computer-aided manufacture (CAD/CAM) accuracy of dental drill guides for application in guided surgery. Today, the availability of three-dimensional (3D) desktop printers allows for the cost-effective production of drill guides by dental laboratories. Our investigations show the accuracy of produced guides by eliminating influencing factors that exist in the guided surgery workflow. To investigate this accuracy, a method was developed to evaluate the CAD/CAM production technology apart from sources of error from cone beam computed tomography (CBCT) scans, intraoral scans, software or human error. By using a CAD/CAM-milled idealized reference model, as well as CAD data from a scanned dental model with integrated reference spheres, drill guides with different offset values were designed using the coDiagnostiX® implant-planning software. The Bone Level Roxolid® SLActive® implant system (length 8 mm, diameter 3.3 mm) was chosen. The virtual position in relation to both the drill guide and the reference model was determined based on the planning data and exported STL files, respectively. Virtual and physical measurements were performed through the center coordinates of the used drill sleeves (T-sleeve: 5 mm), by applying a defined reference coordinate system (RCS) of the dental model. Drill guide templates were printed using a FotoDent® guide on a dental desktop printer (D30), based on a defined digital workflow. After insertion of the respective drill sleeves, surgical guides were secured on the reference models using quadrangular fixation, thus allowing a tactile measurement by applying a coordinate measurement device for determination of physical position relation. Through the central points of the drill sleeves, both the coronal and apical points of the planned implant drilling as well as angular deviation were calculated and reviewed against the CAD measurements. On average, a deviation of 0.25 degrees of the planned implant was detected.
本文描述了用于引导手术的牙科钻导板的计算机辅助设计/计算机辅助制造（CAD/CAM）精度。如今，三维（3D）桌面打印机的出现使牙科实验室能够经济高效地生产钻导板。我们的研究通过消除引导手术工作流程中存在的影响因素来展示所生产导板的精度。为了研究这种精度，开发了一种方法来评估CAD/CAM生产技术，排除锥束计算机断层扫描（CBCT）扫描、口内扫描、软件或人为误差等误差来源。通过使用CAD/CAM铣削的理想化参考模型以及来自带有集成参考球的扫描牙科模型的CAD数据，使用coDiagnostiX®种植体规划软件设计了具有不同偏移值的钻导板。选择了骨水平Roxolid® SLActive®种植体系统（长度8毫米，直径3.3毫米）。分别根据规划数据和导出的STL文件确定相对于钻导板和参考模型的虚拟位置。通过应用牙科模型的定义参考坐标系（RCS），通过所用钻套（T型套：5毫米）的中心坐标进行虚拟和物理测量。基于定义的数字工作流程，使用FotoDent®导板在牙科桌面打印机（D30）上打印钻导板模板。插入相应的钻套后，使用四边形固定将手术导板固定在参考模型上，从而通过应用坐标测量设备进行触觉测量，以确定物理位置关系。通过钻套的中心点，计算计划种植体钻孔的冠部和根尖点以及角度偏差，并与CAD测量结果进行对比。平均而言，检测到计划种植体有0.25度的偏差。
