To compare the accuracy of complete-arch scans and quadrant scans obtained using a direct chairside intraoral scanner. Intraoral scans were obtained from 20 adults without missing teeth except for the third molar. Maxillary and mandibular complete-arch scans were carried out, and 4 quadrant scans for each arch were performed to obtain right posterior, right anterior, left anterior, and left posterior quadrant scans. Complete-arch scans and quadrant scans were compared with corresponding model scans using best-fit surface-based registration. Shell/shell deviations were computed for complete-arch scans and quadrant scans and compared between the complete-arch scans and each quadrant scans. In addition, shell/shell deviations were calculated also for each individual tooth in complete-arch scans to evaluate factors which influence the accuracy of intraoral scans. Complete-arch scans showed relatively greater errors (0.09 ~ 0.10 mm) when compared to quadrant scans (0.05 ~ 0.06 mm). The errors were greater in the maxillary scans than in the mandibular scans. The evaluation of errors for each tooth showed that the errors were greater in posterior teeth than in anterior teeth. Comparing the right and left errors, the right side posterior teeth showed a more substantial variance than the left side in the mandibular scans. The scanning accuracy has a difference between complete-arch scanning and quadrant scanning, particularly in the posterior teeth. Careful consideration is needed to avoid scanning inaccuracy for maxillary or mandibular complete-arch, particularly in the posterior area because a complete-arch scan might have potential error than a quadrant scan.

中文翻译：

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完整牙弓扫描和象限扫描的口内扫描准确性比较

为了比较使用直接椅旁口腔内扫描仪获得的完整牙弓扫描和象限扫描的准确性。从20名成年人中进行了口内扫描，除了第三颗臼齿以外，没有牙齿缺失。进行上颌和下颌完整牙弓扫描，并对每个牙弓进行4个象限扫描，以获得右后，右前，左前和左后象限扫描。使用最适合的基于曲面的配准，将完整的弓形扫描和象限扫描与相应的模型扫描进行比较。计算完整拱形扫描和象限扫描的壳/壳偏差，并在完整拱形扫描和每个象限扫描之间进行比较。此外，还对完整牙弓扫描中的每个牙齿计算了壳/壳偏差，以评估影响口内扫描准确性的因素。与象限扫描（0.05〜0.06 mm）相比，完整弓形扫描显示相对较大的误差（0.09〜0.10 mm）。上颌扫描的误差比下颌扫描的误差大。评估每颗牙齿的误差表明，后牙的误差大于前牙的误差。比较左右错误，右侧后牙比下颌扫描的左侧显示出更大的差异。扫描精度在完整弓形扫描和象限扫描之间有差异，特别是在后牙方面。需要仔细考虑以避免上颌或下颌完整牙弓的扫描误差，