数字化技术在可摘局部义齿基牙精准修复中的应用
Application of digital technology in precise fixed restoration of abutment tooth in removable partial denture

摘要：目的 研究数字化技术在可摘局部义齿基牙精准修复中的应用。方法 设计并模拟制作包含固定义齿预备后基牙的可摘活动义齿简化模型，Trios口内扫描仪分10次扫描该简化模型，获得包含预备后基牙与可摘活动义齿基板三维空间信息的简化模型数据。在该预备后基牙上分别制作10个计算机辅助设计/制作(CAD/CAM)树脂冠，以及10个统一标准制作的手工树脂冠。3Shape D700模型扫描仪舱扫上述20个树脂冠，获得STL格式数据，并导入Geomagic Qualify 12.0软件对扫描数据进行两两之间最佳拟合对齐及3D分析，结果以配准模型间的偏差输出，独立样本t检验分析数据差异并实物检验两组树脂冠与可摘义齿基板的适合性。结果 CAD/CAM 组平均偏差均值、标准差均值分别为52.13/－57.53、75.53μm，低于手工组的77.42/－68.91μm和96.84μm，差异具有统计学意义(P<0.05)。两种方法设计制作的树脂冠均能顺利就位。结论 针对位于可摘活动义齿基板范围内的预备后基牙，采用口内扫描结合CAD/CAM技术制作的全冠精度高于传统手工方法制作的全冠，二者均可满足临床需求。
ABSTRACT: Objective To investigate the application of digital technology in precise restoration of removable partial denture based crown. Methods A simplified model of removable partial denture with prepared abutment tooth was designed and fabricated. The simplified model was repeatedly scanned 10 times by Trios intraoral scanner, and the simplified model data including 3D spatial information between the prepared abutment and removable partial denture baseplate was obtained. The following crowns were made on the abutment with removable denture baseplate information: 10 CAD/CAM (computer-aided design/manufacture) resin crowns; 10 resin crowns were handmade by the same technician according to the unified design standard. Then 3 Shape D700 model scanner was used to scan the 20 resin crowns mentioned above and the STL format data were obtained. These data were imported into the Geomagic Qualify12.0 software; the optimal fitting alignment and 3D analysis were carried out between two pairs of repeated scanning data. The results were output by the mean deviation between the registration models and data differences were analyzed by independent sample t test. Fitness of two groups of resin crowns with the simplified model was tested by inserting the crowns into the simplified model respectively. Results The mean deviation of CAD/CAM group was 52.13/－57.53μm, and the mean standard deviation was 75.53μm, which was significantly lower than that of the handmade group (77.42/－68.91μm, 96.84μm, P<0.05). The resin crowns fabricated by both methods could be placed smoothly. Conclusion The precision of full crown made by intraoral scanning combined with CAD/CAM technology to retain original removable denture is higher than that of the traditional manual method. Both of the crowns can meet the clinical requirements