Department of Prosthodontics, Biomaterials Research Center, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
Department of Research Analytics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, India; Department of Conservative Dentistry and Bucofacial Prostheses, Faculty of Odontology, University Complutense of Madrid, Madrid, Spain; Department of Prosthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
J Dent. 2024 Nov;150:105325. doi: 10.1016/j.jdent.2024.105325. Epub 2024 Sep 3.
This study aimed to assess the effect of the "cut-out rescan" strategy on the accuracy of intraoral digital scans from 25° convergent implants positioned at two distinct depths.
Two customized models were fabricated, each designated to receive two posterior converged implant fixtures: one at a depth of 1 mm and the other at a depth of 4 mm. Initially, the models were scanned as reference casts using a lab scanner. The test group was involved in scanning the 1-mm and 4-mm implant models using an intraoral scanner in the following order: (1) scanning the 1-mm (T1; n = 10) and (2) 4-mm (T4; n = 10) implant groups with scan bodies connected to both fixtures in each model; (3) cut-out rescan (COR) in the 1-mm (COR1; n = 10) and (4) 4-mm (COR4; n = 10) models, leading to 40 digital files in standard tessellation language format. The mean absolute deviation (MAD), in terms of trueness and precision, between the experimental and control scans was assessed through the alignment of their respective datasets using three-dimensional analysis software. Two-way analysis of variance (ANOVA) and Levene's tests were used to analyze the data.
The COR4 group exhibited the highest MAD, indicative of both trueness and precision (Mean ±SD: 55.659 ±34.802). In contrast, the T1 group demonstrated the lowest MAD (Mean ±SD: 43.225 ±19.237). However, the ANOVA analysis showed no significant influence of depth (P = 0.506) or type of scan (P = 0.442) on the MAD. Precision also did not differ significantly across groups (P = 0.071).
The cut-out rescan approach demonstrated an accuracy comparable to that of the one-time scan method.
Digital intraoral scanning provides clinicians with a range of tools to navigate challenging conditions in which conventional methods may prove difficult, such as cases involving angled adjacent implants. In these scenarios, the cut-out rescan tool serves as a valuable resource, aiding clinicians in overcoming the challenges associated with impression-making owing to the convergence of placed implants.
本研究旨在评估“切出重扫”策略对两种不同深度的 25°汇聚种植体的口内数字扫描准确性的影响。
制作了两个定制模型，每个模型都设计用来接收两个后牙汇聚种植体修复体：一个深度为 1 毫米，另一个深度为 4 毫米。首先，使用实验室扫描仪对模型进行扫描，作为参考模型。实验组按照以下顺序使用口内扫描仪扫描 1 毫米和 4 毫米种植体模型：（1）扫描 1 毫米（T1；n = 10）和（2）4 毫米（T4；n = 10）种植体模型，扫描体连接到每个模型中的两个修复体；（3）1 毫米（COR1；n = 10）和（4）4 毫米（COR4；n = 10）模型的切出重扫，共生成 40 个标准 tessellation language 格式的数字文件。通过使用三维分析软件对齐各自数据集，评估实验扫描和对照扫描之间在准确性和精密度方面的平均绝对偏差（MAD）。使用双向方差分析（ANOVA）和 Levene 检验对数据进行分析。
COR4 组的 MAD 值最高，表明准确性和精密度都较高（均值 ±标准差：55.659 ±34.802）。相比之下，T1 组的 MAD 值最低（均值 ±标准差：43.225 ±19.237）。然而，ANOVA 分析表明，深度（P = 0.506）或扫描类型（P = 0.442）对 MAD 均无显著影响。各组之间的精密度也无显著差异（P = 0.071）。
切出重扫方法的准确性可与单次扫描方法相媲美。
数字化口内扫描为临床医生提供了一系列工具，用于解决常规方法可能难以处理的挑战性情况，例如涉及相邻植入物成角的情况。在这些情况下，切出重扫工具是一种有价值的资源，可帮助临床医生克服因植入物放置而导致的印模制作挑战。
