Department of Prosthodontics, Faculty of Dental Medicine, Lebanese University, Beirut, Lebanon, Phone: +9613620654, e-mail:
Department of Prosthodontics, Faculty of Dental Medicine, Lebanese University, Beirut, Lebanon.
J Contemp Dent Pract. 2020 Dec 1;21(12):1384-1388.
This study aimed to digitally analyze the 3-dimensional variations existing between conventional impressions and intraoral scans made in edentulous maxillae.
Ten ( = 10) edentulous maxillae of patients seeking a maxillary complete denture were scanned using an intraoral scanner. The same participants were subject to the conventional impression procedure for the fabrication of maxillary complete dentures. The dentures' intaglio surfaces were scanned and superimposed over their corresponding IOS files with a 2-base best-fit alignment. Deviation analyses were calculated using the digital subtraction technique. Four anatomical regions were preselected to evaluate the deviations at these sites (posterior palatal seal, anterior border seal, the crest of the ridge and palate).
Based on the results and color maps of all selected regions, the overall difference between the two scans [IOS and denture intaglio surface scanning (DISS)] was not significant. The IOS technique allowed for predictable outcomes of treatment compared to those observed with conventional impression. The palatal area seems to be the region with the least deviation, while the highest incidence of discrepancy was reported in the anterior border seal.
Within the limitations of this study, the IOS technique allowed the capturing of intraoral tissues and their immediate interpretation and transfer to a designing software making the impression procedure faster and easier.
The computer-aided design (CAD)/computer-aided manufacturing (CAM) technologies can help overcome many limitations related to conventional impressions and therefore should be well investigated to improve the edentulous patient's quality of life.
本研究旨在对无牙上颌的常规印模和口内扫描之间存在的三维变化进行数字化分析。
对 10 名（=10）寻求上颌全口义齿的无牙上颌患者进行口内扫描仪扫描。同一组患者接受常规印模程序以制作上颌全口义齿。义齿的凹面被扫描，并与相应的 IOS 文件以 2 个基最佳拟合对齐方式进行叠加。使用数字减法技术计算偏差分析。选择四个解剖区域来评估这些部位的偏差（后腭封闭，前边界封闭，嵴顶和 palate）。
基于所有选定区域的结果和彩色地图，两种扫描[IOS 和义齿凹面扫描（DISS）]之间的总体差异不显著。与常规印象相比，IOS 技术允许治疗结果具有可预测性。腭区似乎是偏差最小的区域，而在前边界密封处报告了最高的差异发生率。
在本研究的限制范围内，IOS 技术允许捕获口腔内组织，并立即对其进行解释和转移到设计软件，使印模程序更快，更容易。
计算机辅助设计（CAD）/计算机辅助制造（CAM）技术可以帮助克服与常规印象相关的许多限制，因此应该进行充分研究，以提高无牙患者的生活质量。
