Department of Prosthodontics, Faculty of Dentistry, Istinye University, İstanbul, Turkey.
Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland.
Clin Implant Dent Relat Res. 2023 Jun;25(3):502-510. doi: 10.1111/cid.13190. Epub 2023 Feb 10.
Accuracy of intraoral implant scans may be affected by the region of the implant and the type of the intraoral scanner (IOSs). However, there is limited knowledge on the scan accuracy of multiple implants placed for an implant-supported fixed partial denture (FPD) in different partially edentulous situations when digitized by using different IOSs.
To investigate the effect of IOS and FPD situation on the scan accuracy of two implants when partial-arch scans were performed.
Tissue level implants were placed in 3 maxillary models with implant spaces either at right first premolar and right first molar sites (Model 1, 3-unit FPD), at right canine and right first molar sites (Model 2, 4-unit FPD), or at lateral incisor sites (Model 3, 4-unit FPD). Reference standard tessellation language (STL) files of the models were generated by using an optical scanner (ATOS Capsule 200MV120). Two IOSs (CEREC Primescan [CP] and TRIOS 3 [TR]) were used to perform partial-arch scans (test-scans) of each model (n = 14), which were exported in STL format. A metrology-grade analysis software (GOM Inspect 2018) was used to superimpose test-scan STLs over the reference STL to calculate 3D distance, inter-implant distance, and angular (mesiodistal and buccopalatal) deviations. Trueness and precision analyses were performed by using bootstrap analysis of variance followed by Welch tests with Holm correction (α = 0.05).
Trueness of the scans was affected by IOS and FPD situation when 3D distance deviations were considered, while inter-implant distance, mesiodistal angular, and buccopalatal angular deviations were only affected by the FPD situation (p < 0.001). Scan precision was affected by the interaction between the IOSs and the FPD situation when 3D distance and buccopalatal angular deviations were concerned, while IOSs and FPD situation were effective when all deviations were concerned (p≤ 0.001). When 3D distance deviations were considered, CP scans had higher accuracy TR scans in Models 1 and 3 (p ≤ 0.002), and the Model 1 scans had the highest accuracy (p < 0.001). When inter-implant distance deviations were considered, Model 1 scans had the highest accuracy with CP and higher accuracy than Model 2 when TR was used (p ≤ 0.030). When mesiodistal angular deviations were considered, Model 1 scans had the highest accuracy (p ≤ 0.040). When buccopalatal angular deviations were considered, Model 1 scans had the highest accuracy among models when CP was used (p ≤ 0.020).
Posterior 3-unit fixed partial denture implant scans, CP scans, and combination of these two factors had accuracy either similar to or better than their tested counterparts.
种植体扫描的准确性可能受到种植体部位和口内扫描仪（IOS）类型的影响。然而，当使用不同的 IOS 对不同部分缺牙情况下用于支持种植体固定修复体（FPD）的多个种植体进行数字化扫描时，关于多个种植体扫描准确性的知识有限。
研究 IOS 和 FPD 情况对部分牙弓扫描时两个种植体扫描准确性的影响。
在 3 个上颌模型中放置组织水平种植体，种植体空间位于右侧第一前磨牙和右侧第一磨牙部位（模型 1，3 单位 FPD）、右侧犬齿和右侧第一磨牙部位（模型 2，4 单位 FPD）或侧切牙部位（模型 3，4 单位 FPD）。使用光学扫描仪（ATOS Capsule 200MV120）生成模型的参考标准 tessellation language（STL）文件。使用两种 IOS（CEREC Primescan [CP] 和 TRIOS 3 [TR]）对每个模型（n=14）进行部分牙弓扫描（测试扫描），并以 STL 格式导出。使用计量级分析软件（GOM Inspect 2018）将测试扫描的 STL 叠加到参考 STL 上，以计算 3D 距离、种植体间距离和角度（近远中向和颊舌向）偏差。使用 bootstrap 方差分析和 Welch 检验（Holm 校正，α=0.05）进行准确性和精密度分析。
当考虑 3D 距离偏差时，扫描的准确性受到 IOS 和 FPD 情况的影响，而种植体间距离、近远中向角度和颊舌向角度偏差仅受到 FPD 情况的影响（p<0.001）。当考虑 3D 距离和颊舌向角度偏差时，扫描精度受到 IOS 和 FPD 情况之间的相互作用的影响，而当考虑所有偏差时，IOS 和 FPD 情况均有效（p≤0.001）。当考虑 3D 距离偏差时，CP 扫描在模型 1 和模型 3 中的准确性高于 TR 扫描（p≤0.002），且模型 1 扫描的准确性最高（p<0.001）。当考虑种植体间距离偏差时，CP 扫描的模型 1 扫描具有最高的准确性，而 TR 扫描的模型 2 扫描具有最高的准确性（p≤0.030）。当考虑近远中向角度偏差时，模型 1 扫描的准确性最高（p≤0.040）。当考虑颊舌向角度偏差时，CP 扫描的模型 1 扫描在所有模型中具有最高的准确性（p≤0.020）。
后牙 3 单位固定修复体种植体扫描、CP 扫描以及这两种因素的组合在准确性方面与测试结果相似或更好。
