Kwon Sumin, Park Eun-Jin
Resident, Department of Dentistry, Ewha Womans University Mokdong Hospital, Seoul, Republic of Korea.
Professor, Department of Dentistry, Ewha Womans University College of Medicine, Seoul, Republic of Korea.
J Prosthet Dent. 2025 May;133(5):1323.e1-1323.e8. doi: 10.1016/j.prosdent.2025.02.015. Epub 2025 Mar 27.
Abutment level scanning using an abutment base-scan body is a convenient option for obtaining digital implant scans. However, few studies have investigated the effects of implant angulation and depth on intraoral scanning accuracy.
The purpose of this in vitro study was to explore ways to improve the accuracy of implant prostheses by comparing intraoral scans at conventional fixture and abutment levels under various implant conditions (angle and depth).
An implant was placed in the maxillary right first molar position of a partially edentulous dentiform at 3 different depths (bone crest level and 3 mm and 6 mm below the crest), and at 3 different angles (0 degrees, 25 degrees, and 35 degrees toward the palatal side). Digital scans were made using a high precision extraoral 3-dimensional (3D) scanner (E4) for the master reference model and an intraoral scanner (i700) for the test model. A conventional scan body was used in the control group, and an abutment base-scan body was used in the experimental group. Each scan was performed 10 times by a single clinician. The standard tessellation language (STL) files of the scans were analyzed using a 3D metrology software program (Gom Inspect) and superimposed on the occlusal surfaces, and the root mean square (RMS) error discrepancies were calculated at 5 specific points on the scan body. The accuracy of the control and experimental groups was compared by converting the deviation values to absolute values and averaging them based on the depth and angle conditions. Statistical analysis included independent samples t tests, Welch t tests, and 1-way analysis of variance (ANOVA) with a Scheffé post hoc test to compare mean differences among groups based on the implant angle and depth (α=.05).
The experimental group showed significantly higher accuracy (P<.05) than the control group under most conditions. A significant correlation between the implant angulation and depth was observed in the control group. One-way ANOVA, followed by a Scheffé post hoc test, revealed that the control group showed significantly higher accuracy at the 0-mm depth condition and 0-degree condition (P<.05). However, the experimental group showed significantly higher accuracy in the 3-mm depth condition (P<.05). The experimental group also demonstrated higher accuracy (P<.05) with shorter visible supramucosal lengths.
The accuracy of intraoral scanning using the abutment base-scan body system was comparable with that of the conventional fixture level digital scans with scan bodies. Additionally, when the implant is angled toward the palatal side or is deeply placed, the abutment-level scan body can be a useful option during digital scanning.
使用基台基部扫描体进行基台水平扫描是获取数字化种植体扫描的便捷方法。然而，很少有研究调查种植体角度和深度对口腔内扫描精度的影响。
本体外研究的目的是通过比较在各种种植体条件（角度和深度）下常规种植体水平和基台水平的口腔内扫描，探索提高种植修复体精度的方法。
在部分无牙颌牙模型的上颌右侧第一磨牙位置植入一枚种植体，种植体位于3个不同深度（牙槽嵴顶水平以及牙槽嵴顶以下3mm和6mm），并具有3个不同角度（向腭侧0度、25度和35度）。使用高精度口外三维（3D）扫描仪（E4）对主参考模型进行数字化扫描，使用口腔内扫描仪（i700）对测试模型进行扫描。对照组使用常规扫描体，实验组使用基台基部扫描体。每次扫描由一名临床医生进行10次。使用三维计量软件程序（Gom Inspect）分析扫描的标准镶嵌语言（STL）文件，并将其叠加在咬合面上，计算扫描体上5个特定点的均方根（RMS）误差差异。通过将偏差值转换为绝对值并根据深度和角度条件进行平均，比较对照组和实验组的精度。统计分析包括独立样本t检验、韦尔奇t检验以及单因素方差分析（ANOVA），并采用谢弗事后检验，以比较基于种植体角度和深度的组间平均差异（α = 0.05）。
在大多数情况下，实验组的精度显著高于对照组（P < 0.05）。在对照组中观察到种植体角度和深度之间存在显著相关性。单因素方差分析，随后进行谢弗事后检验，结果显示对照组在0mm深度条件和0度条件下精度显著更高（P < 0.05）。然而，实验组在3mm深度条件下精度显著更高（P < 0.05）。实验组在较短的可见龈上长度时也显示出更高的精度（P < 0.05）。
使用基台基部扫描体系统进行口腔内扫描的精度与使用扫描体进行常规种植体水平数字化扫描的精度相当。此外，当种植体向腭侧倾斜或植入较深时，基台水平扫描体在数字化扫描过程中可能是一个有用的选择。
