Post Graduate student, Department of Prosthodontics, Faculty of Dentistry, Shahed University, Tehran, Iran.
Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Shahed University, Tehran, Iran.
J Prosthet Dent. 2021 Nov;126(5):665-670. doi: 10.1016/j.prosdent.2020.08.017. Epub 2020 Oct 16.
The accuracy of intraoral and extraoral scanners for different models of edentulousness is unclear.
The purpose of this in vitro evaluation was to determine the accuracy (trueness and precision) of complete-arch scans made by 3 intraoral and 1 extraoral scanners compared with an industrial 3D scanner.
Digital scans were made of a reference cast with 3 intraoral scanners (CEREC Omnicam; Dentsply Sirona, TRIOS 3; 3shape A/S; Carestream CS 3600; Carestream Dental) and an extraoral scanner (Deluxe scanner; Open Technologies). A dental maxilla model was used for tooth preparation for ceramic restorations with a shoulder finishing line. Maxillary right central and lateral incisors and third molar and maxillary left second premolar and first and third molar teeth were removed. One operator scanned the reference cast 10 times with each scanner. All the recorded standard tessellation language (STL) files were imported into an inspection software program and individually overlaid on the STL file for the reference model made by the 3D scanner. The measured distance between the distal point of the maxillary left second molar tooth and the mesial point of the maxillary left first premolar was defined as distance 1; distance 2 was defined as the distance between the mesial point of the maxillary second molar tooth and the distal point of the maxillary right first premolar tooth. The Levene test for homoscedasticity of variances was used to evaluate precision, and a 2-way repeated-measures ANOVA and Bonferroni-corrected Student t tests were used to evaluate trueness (α=.05).
A statistically significant difference was found between the Carestream scanner and the other scanners when scanning both mucosa and teeth. The Carestream scanner had the lowest accuracy and highest magnitude mean deviation of all the scanners.
Obtaining an accurate partial-arch impression is still challenging for some intraoral scanners. The Carestream scanner's trueness was outside the acceptable range. However, other scanners tested here appeared to be suitable alternatives to conventional impression techniques.
不同类型无牙颌模型的口腔内和口腔外扫描仪的准确性尚不清楚。
本体外评估的目的是确定 3 种口腔内扫描仪和 1 种口腔外扫描仪与工业 3D 扫描仪相比，全牙弓扫描的准确性（准确性和精密度）。
使用 3 种口腔内扫描仪（CEREC Omnicam；登士柏西诺德，TRIOS 3；3shape A/S；Carestream CS 3600；Carestream Dental）和 1 种口腔外扫描仪（Deluxe scanner；Open Technologies）对参考模型进行数字扫描。使用带有肩台成型线的陶瓷修复体进行牙预备，制作一个牙科上颌模型。上颌右侧中切牙、侧切牙和第三磨牙以及上颌左侧第二前磨牙、第一磨牙和第三磨牙被去除。一名操作员使用每个扫描仪对参考模型进行了 10 次扫描。将所有记录的标准三角测量语言（STL）文件导入到检查软件程序中，并分别与 3D 扫描仪制作的参考模型的 STL 文件重叠。定义上颌左侧第二磨牙远中点与上颌左侧第一前磨牙近中点之间的距离为距离 1；定义上颌第二磨牙近中点与上颌右侧第一前磨牙远中点之间的距离为距离 2。使用方差同质性的莱文检验评估精密度，使用双向重复测量方差分析和 Bonferroni 校正学生 t 检验评估准确性（α=.05）。
当扫描黏膜和牙齿时，Carestream 扫描仪与其他扫描仪之间存在统计学显著差异。Carestream 扫描仪的准确性最低，所有扫描仪的平均偏差最大。
对于一些口腔内扫描仪来说，获得准确的部分牙弓印模仍然具有挑战性。Carestream 扫描仪的准确性超出了可接受范围。然而，这里测试的其他扫描仪似乎是传统印模技术的合适替代品。
