Precise data are a prerequisite for accurately fitting restorations. Therefore, intraoral scanners have to be reliable. Data on differences between the same model of intraoral scanning systems are lacking. This in vitro study evaluated differences in the scanning accuracy of a partially edentulous maxilla between combinations of new intraoral scanners of a single model from the same manufacturer (Primescan; Dentsply Sirona) and several calibration aids. The in vitro reference model simulated a maxilla with 6 prepared teeth for a complete arch fixed partial denture. Five precision ceramic balls were used to detect dimensional deviation between the reference model and the scan. Distances were divided into 4 categories, from short distances between 2 neighboring precision balls to the cross-arch distance with the scan path comprising all 5 balls. For each combination of 4 new intraoral scanners and their respective calibration aids, 12 model registrations were generated. The data were statistically analyzed using ANOVA (α=.05). Distance deviations increased with increasing scan path length and were significantly affected by the covariates “scanner” (≤.023) and, for 3 of 4 distance categories, the “calibration aid” (short, medium, and long distances: ≤.013). For short and medium distances, acceptable scanning results were achieved for all test groups. The largest deviation was 539 µm for the cross-arch distance. Scanning accuracy depends on the scanner and the calibration aid used, in particular, for spans exceeding a single quadrant.

中文翻译：

---

校准辅助设备和口内扫描仪对部分无牙颌上颌配准的影响：一项体外研究

精确的数据是准确拟合修复体的先决条件。因此，口腔内扫描仪必须可靠。缺乏同一型号口腔内扫描系统之间差异的数据。这项体外研究评估了同一制造商的单一型号新型口腔内扫描仪（Primescan；Dentsply Sirona）与多种校准辅助设备的组合在部分无牙颌上颌扫描精度方面的差异。体外参考模型模拟了带有 6 颗预备牙的上颌骨，用于全牙弓固定局部义齿。使用五个精密陶瓷球来检测参考模型和扫描之间的尺寸偏差。距离分为 4 类，从 2 个相邻精密球之间的短距离到扫描路径包含所有 5 个球的跨拱距离。对于 4 个新口腔内扫描仪及其各自的校准辅助工具的每种组合，生成 12 个模型注册。使用方差分析（α=.05）对数据进行统计分析。距离偏差随着扫描路径长度的增加而增加，并且受协变量“扫描仪”(≤.023) 和 4 个距离类别中的 3 个“校准辅助”（短距离、中距离和长距离：≤.013）的显着影响。对于短距离和中距离，所有测试组都获得了可接受的扫描结果。跨拱距离的最大偏差为 539 µm。扫描精度取决于扫描仪和所使用的校准辅助设备，特别是对于超过单个象限的跨度。