Ender Andreas, Zimmermann Moritz, Attin Thomas, Mehl Albert
Division for Computerized Restorative Dentistry, Clinic for Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zürich, Zürich, Switzerland.
Clinic for Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zürich, Zürich, Switzerland.
Clin Oral Investig. 2016 Sep;20(7):1495-504. doi: 10.1007/s00784-015-1641-y. Epub 2015 Nov 7.
Quadrant impressions are commonly used as alternative to full-arch impressions. Digital impression systems provide the ability to take these impressions very quickly; however, few studies have investigated the accuracy of the technique in vivo. The aim of this study is to assess the precision of digital quadrant impressions in vivo in comparison to conventional impression techniques.
Impressions were obtained via two conventional (metal full-arch tray, CI, and triple tray, T-Tray) and seven digital impression systems (Lava True Definition Scanner, T-Def; Lava Chairside Oral Scanner, COS; Cadent iTero, ITE; 3Shape Trios, TRI; 3Shape Trios Color, TRC; CEREC Bluecam, Software 4.0, BC4.0; CEREC Bluecam, Software 4.2, BC4.2; and CEREC Omnicam, OC). Impressions were taken three times for each of five subjects (n = 15). The impressions were then superimposed within the test groups. Differences from model surfaces were measured using a normal surface distance method. Precision was calculated using the Perc90_10 value. The values for all test groups were statistically compared.
The precision ranged from 18.8 (CI) to 58.5 μm (T-Tray), with the highest precision in the CI, T-Def, BC4.0, TRC, and TRI groups. The deviation pattern varied distinctly depending on the impression method. Impression systems with single-shot capture exhibited greater deviations at the tooth surface whereas high-frame rate impression systems differed more in gingival areas. Triple tray impressions displayed higher local deviation at the occlusal contact areas of upper and lower jaw.
Digital quadrant impression methods achieve a level of precision, comparable to conventional impression techniques. However, there are significant differences in terms of absolute values and deviation pattern.
With all tested digital impression systems, time efficient capturing of quadrant impressions is possible. The clinical precision of digital quadrant impression models is sufficient to cover a broad variety of restorative indications. Yet the precision differs significantly between the digital impression systems.
象限印模通常用作全牙弓印模的替代方法。数字印模系统能够非常快速地获取这些印模；然而，很少有研究在体内研究该技术的准确性。本研究的目的是评估与传统印模技术相比，数字象限印模在体内的精度。
通过两种传统方法（金属全牙弓托盘，CI，和三联托盘，T型托盘）以及七种数字印模系统（Lava True Definition扫描仪，T-Def；Lava椅旁口腔扫描仪，COS；Cadent iTero，ITE；3Shape Trios，TRI；3Shape Trios Color，TRC；CEREC Bluecam，软件4.0，BC4.0；CEREC Bluecam，软件4.2，BC4.2；以及CEREC Omnicam，OC）获取印模。对五名受试者（n = 15）中的每一名进行三次印模采集。然后在测试组内对印模进行叠加。使用正常表面距离方法测量与模型表面的差异。使用Perc90_10值计算精度。对所有测试组的值进行统计学比较。
精度范围为18.8（CI）至58.5μm（T型托盘），CI、T-Def、BC4.0、TRC和TRI组的精度最高。偏差模式根据印模方法的不同而明显不同。单次捕获的印模系统在牙齿表面表现出更大的偏差，而高帧率印模系统在牙龈区域的差异更大。三联托盘印模在上颌和下颌的咬合接触区域显示出更高的局部偏差。
数字象限印模方法达到了与传统印模技术相当的精度水平。然而，在绝对值和偏差模式方面存在显著差异。
使用所有测试的数字印模系统，都能够高效地获取象限印模。数字象限印模模型的临床精度足以涵盖广泛的修复适应症。然而，数字印模系统之间的精度差异显著。
