Rutkūnas Vygandas, Gečiauskaitė Agnė, Jegelevičius Darius, Vaitiekūnas Mantas
Eur J Oral Implantol. 2017;10 Suppl 1:101-120.
The use of intraoral scanners (IOS) for making digital implant impressions is increasing. However, there is a lack of evidence on the accuracy of IOS compared with conventional techniques. Therefore, the aim of this systematic review was to collect evidence on the accuracy of digital implant impression techniques, as well as to identify the main factors influencing the accuracy outcomes.
Two reviewers searched electronic databases in November, 2016. Controlled vocabulary, free-text terms, and defined inclusion and exclusion criteria were used. Publications in English language evaluating the accuracy outcomes of digital implant impressions were identified. Pooled data were analysed qualitatively and pertinent data extracted.
In total, 16 studies fulfilled the inclusion criteria: one in vivo and 15 in vitro studies. The clinical study concluded that angular and distance errors were too large to be acceptable clinically. Less accurate findings were reported by several in vitro studies as well. However, all in vitro studies investigating the accuracy of newer generation IOS indicated equal or even better results compared with the conventional techniques. Data related to the influence of distance and angulation between implants, depth of placement, type of scanner, scanning strategy, characteristics of scanbody and reference scanner, operator experience, etc were analysed and summarised. Linear deviations (means) of IOS used in in vitro studies ranged from 6 to 337 µm. Recent studies indicated small angle deviations (0.07-0.3°) with digital impressions. Some studies reported that digital implant impression accuracy was influenced by implant angulation, distance between the implants, implant placement depth and operator experience.
According to the results of this systematic review and based on mainly in vitro studies, digital implant impressions offer a valid alternative to conventional impressions for single- and multi-unit implant-supported restorations. Further in vivo studies are needed to substantiate the use of currently available IOS, identify factors potentially affecting accuracy and define clinical indications for specific type of IOS. Data on Data on accuracy OF digital records, as well as accuracy of printed or milled models for implant-supported restorations, are of high relevance and are still lacking. Conflict-of-interest and funding statement: The authors state there is no conflict of interest.
口腔内扫描仪（IOS）用于制作数字化种植体印模的情况日益增多。然而，与传统技术相比，IOS准确性方面的证据不足。因此，本系统评价的目的是收集数字化种植体印模技术准确性的证据，并确定影响准确性结果的主要因素。
两名评价者于2016年11月检索了电子数据库。使用了控制词汇、自由文本词以及明确的纳入和排除标准。识别出以英文发表的评估数字化种植体印模准确性结果的文献。对汇总数据进行定性分析并提取相关数据。
共有16项研究符合纳入标准：1项体内研究和15项体外研究。临床研究得出结论，角度和距离误差过大，在临床上无法接受。多项体外研究也报告了不太准确的结果。然而，所有研究新一代IOS准确性的体外研究均表明，与传统技术相比，结果相同甚至更好。分析并总结了与种植体之间的距离和角度、植入深度、扫描仪类型、扫描策略、扫描体和参考扫描仪的特性、操作者经验等影响因素相关的数据。体外研究中使用的IOS的线性偏差（均值）范围为6至337μm。近期研究表明数字化印模的角度偏差较小（0.07 - 0.3°）。一些研究报告称，数字化种植体印模的准确性受种植体角度、种植体之间的距离、种植体植入深度和操作者经验的影响。
根据本系统评价的结果，主要基于体外研究，数字化种植体印模为单颗和多颗种植体支持的修复体提供了一种替代传统印模的有效方法。需要进一步的体内研究来证实目前可用的IOS的使用情况，识别可能影响准确性的因素，并确定特定类型IOS的临床适应证。关于数字化记录的准确性以及种植体支持修复体的打印或铣削模型的准确性的数据具有高度相关性且仍然缺乏。利益冲突和资金声明：作者声明不存在利益冲突。
