Department of Restorative, Preventive and Pediatric Dentistry, School of Dental Medicine, University of Bern, Freiburgstrasse 7, 3010, Bern, Switzerland.
Department of Periodontology and Operative Dentistry, University Medical Center of the Johannes-Gutenberg-University Mainz, Mainz, Germany.
Sci Rep. 2021 Feb 8;11(1):3340. doi: 10.1038/s41598-021-82942-6.
The aim of this research was to determine ex vivo the influence on accuracy of five different embedding media, for investigative and educational purposes, and one electronic apex locator. 110 human extracted mature roots of permanent single-rooted human teeth were used. The roots were embedded in alginate, stick sponge, 2% agar-agar and 6% and 12% gelatin. The actual working length to the physiological foramen was determined under a stereo-microscope (16 ×) and the electronic working lengths with the Elements Diagnostic Unit and a K-file ISO 10. The accuracy ranges of the accumulated measurements, when allowing a ± 0.5 mm tolerance, went from 98.2% (6% and 12% gelatin), 93.7% (alginate), 92.8% (2% agar-agar) to 91.7% (sponge). The exact measurements at the physiological foramen ranged from 80.0% (6% gelatin), 76.5% (2% agar-agar), 71.8% (12% gelatin), 68.2% (alginate) to 64.5% (sponge). Although relatively seldom (n = 24), measurements with deviations of more than ± 0.5 mm were also observed; thus, the accuracy of the working length determination results per se can be considered as clinically acceptable. The results of this research allow a recommendation of the investigated embedding media for electronic working length determination models for educational and research purposes in endodontics.
本研究旨在确定五种不同的包埋介质（用于研究和教育目的）和一种电子根尖定位仪对准确性的体外影响。使用了 110 个人类成熟的单根恒牙的人源性拔出恒牙。将牙根包埋在藻酸盐、棒状海绵、2%琼脂和 6%及 12%明胶中。在体视显微镜（16×）下确定到生理根尖的实际工作长度，并使用 Elements Diagnostic Unit 和 K-file ISO 10 确定电子工作长度。在允许±0.5mm 公差的情况下，累积测量的准确性范围从 98.2%（6%和 12%明胶）、93.7%（藻酸盐）、92.8%（2%琼脂）到 91.7%（海绵）。在生理根尖的精确测量值范围从 80.0%（6%明胶）、76.5%（2%琼脂）、71.8%（12%明胶）、68.2%（藻酸盐）到 64.5%（海绵）。尽管相对较少（n=24），也观察到了偏差超过±0.5mm 的测量值；因此，工作长度测定结果的准确性本身可被认为是临床可接受的。本研究的结果允许推荐用于牙髓学教育和研究目的的电子工作长度测定模型的研究包埋介质。
