Jiang Tingting, Lee Sang-Mi, Hou Yanan, Chang Xin, Hwang Hyeon-Shik
Department of Orthodontics, School of Dentistry, Chonnam National University, Gwangju, Korea.
Department of Orthodontics, School of Dentistry, Chonnam National University, Gwangju, Korea.; Department of Orthodontics, Peking University School of Stomatology, Beijing, PR China.
Korean J Orthod. 2016 May;46(3):129-36. doi: 10.4041/kjod.2016.46.3.129. Epub 2016 May 20.
To investigate the dimensional accuracy of digital dental models obtained from the dental cone-beam computed tomography (CBCT) scan of alginate impressions according to the time elapse when the impressions are stored under ambient conditions.
Alginate impressions were obtained from 20 adults using 3 different alginate materials, 2 traditional alginate materials (Alginoplast and Cavex Impressional) and 1 extended-pour alginate material (Cavex ColorChange). The impressions were stored under ambient conditions, and scanned by CBCT immediately after the impressions were taken, and then at 1 hour intervals for 6 hours. After reconstructing three-dimensional digital dental models, the models were measured and the data were analyzed to determine dimensional changes according to the elapsed time. The changes within the measurement error were regarded as clinically acceptable in this study.
All measurements showed a decreasing tendency with an increase in the elapsed time after the impressions. Although the extended-pour alginate exhibited a less decreasing tendency than the other 2 materials, there were no statistically significant differences between the materials. Changes above the measurement error occurred between the time points of 3 and 4 hours after the impressions.
The results of this study indicate that digital dental models can be obtained simply from a CBCT scan of alginate impressions without sending them to a remote laboratory. However, when the impressions are not stored under special conditions, they should be scanned immediately, or at least within 2 to 3 hours after the impressions are taken.
根据藻酸盐印模在环境条件下储存的时间推移，研究通过牙科锥形束计算机断层扫描（CBCT）扫描藻酸盐印模获得的数字牙科模型的尺寸精度。
使用3种不同的藻酸盐材料从20名成年人中获取藻酸盐印模，2种传统藻酸盐材料（Alginoplast和Cavex Impressional）和1种延长灌注藻酸盐材料（Cavex ColorChange）。印模在环境条件下储存，在印模制取后立即通过CBCT扫描，然后每隔1小时扫描6小时。重建三维数字牙科模型后，对模型进行测量并分析数据，以确定根据经过时间的尺寸变化。在本研究中，测量误差范围内的变化被视为临床上可接受的。
所有测量结果均显示，印模制取后的经过时间增加时，尺寸呈下降趋势。尽管延长灌注藻酸盐的下降趋势比其他2种材料小，但材料之间没有统计学上的显著差异。印模制取后3至4小时的时间点之间出现了超出测量误差的变化。
本研究结果表明，可以简单地通过对藻酸盐印模进行CBCT扫描来获得数字牙科模型，而无需将其送到远程实验室。然而，当印模未在特殊条件下储存时，应立即扫描，或至少在印模制取后2至3小时内扫描。
