Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD, USA.
Central Texas Veterans Health Care System, Temple, TX, USA.
J Prosthodont Res. 2020 Oct;64(4):444-453. doi: 10.1016/j.jpor.2019.12.003. Epub 2020 Feb 13.
Within the specialty of prosthodontics, oral impressions are ubiquitous tools utilized to transfer intraoral characteristics such as teeth, implants, and soft tissue into a physical state (stone cast) that is processable in a laboratory setting for the fabrication of dental restorations. In recent years, optical impression systems have become ubiquitous in clinical practice replacing the conventional method of impression making. The purpose of the present study was to evaluate the feasibility and accuracy of computerized optical impression making of edentulous jaws in an in vivo setting.
29 edentulous patients (27 maxillae and five mandibles) underwent conventional impressions as well as computerized optical impressions. The conventional impressions and the resulting stone casts were digitized and superimposed over the computerized/digitized optical impressions in order to obtain information on differences between the two datasets. Statistical analyses were performed to identify relevant deviations.
The overall mean difference between the stone cast, digital scans and the computerized optical scans were 336.7 ± 105.0 µm (n = 32), 363.7 ± 143.1 µm (n = 24), and 272.1 ± 168.5 µm (n = 29), respectively. The visual evaluations revealed highest deviations (≥ 500 µm) in the areas of the soft palate, the sublingual areas, and the vestibule (peripheral seal zone).
Within the limitations of the present study, the investigated scanners were not able currently to fully replace a conventional impression for the fabrication of a complete denture.
在修复牙科领域，口腔印模是一种无处不在的工具，用于将牙齿、种植体和软组织等口腔内特征转化为物理状态（石膏模型），以便在实验室环境中进行加工，制作牙科修复体。近年来，光学印模系统在临床实践中已广泛应用，取代了传统的印模制作方法。本研究旨在评估在体内环境下制作无牙颌计算机光学印模的可行性和准确性。
29 名无牙颌患者（27 例上颌和 5 例下颌）接受了传统印模和计算机光学印模。对传统印模和由此产生的石膏模型进行数字化，并与计算机/数字化光学印模叠加，以获取两组数据集之间差异的信息。进行统计分析以确定相关偏差。
石膏模型、数字扫描和计算机光学扫描之间的总体平均差异分别为 336.7±105.0 µm（n=32）、363.7±143.1 µm（n=24）和 272.1±168.5 µm（n=29）。视觉评估显示，在软腭、舌下区和前庭（外周密封区）等区域存在最大偏差（≥500 µm）。
在本研究的限制范围内，所研究的扫描仪目前还不能完全替代传统印模来制作全口义齿。
