DDS, MSc student, Department of Dentistry, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil.
DDS, MSc, PhD student, Department of Dentistry, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil.
J Prosthet Dent. 2022 Dec;128(6):1310-1317. doi: 10.1016/j.prosdent.2021.02.039. Epub 2021 Apr 15.
The digitalization of completely edentulous arches presents limitations because of the lack of anatomic structures for best-fit alignment during the image generation process of the scanner's software program.
The purpose of this clinical study was to evaluate a new device for intraoral scanning and to analyze its usefulness in capturing the 3-dimensional (3D) position of implants in edentulous mandibular arches.
The 3D positions of 40 implants in 10 participants with fixed interim mandibular prostheses were evaluated by comparing 3 scanning techniques. Images were generated in 2 experimental groups, with digital scan bodies (group SC) and with the scanning device (group SD) and in a control group (group CT) in which images were obtained by laboratory scanning of casts produced from splinted impression copings. The standard tessellation language (STL) files were superimposed by using a reverse engineering software program to measure the 3D coordinate system. Variations in implant linear displacements (Δx, Δy, and Δz), total 3D displacement (Δx+Δy+Δz), and angle projections (ΔθXY, ΔθXZ, and ΔθYZ) were statistically analyzed (α=.05). The distances between the implants were also measured. The Spearman correlation coefficient (α=.05) was used to find the correlation between the 3D coordinates and the distances between the implants.
Group SD had lower values for linear displacement than group SC; however, this difference was not statistically significant except for implant #2. The overall evaluation showed a significant difference with better accuracy for group SD. Concerning angular displacements, group SD showed lesser angular variation for the 3 projection planes. For the distances between the implants, significant differences were only observed for the "all" assessment in which group SD behaved similarly to group CT, while group SC showed the highest values (P<.05). No correlation was detected between the axes (x, y, and z) and the distances between the implants.
The evaluated scanning device led to improved trueness for linear, angular displacements, and distances between implants in mandibular edentulous arches.
由于扫描仪软件程序的图像生成过程中缺乏最佳拟合的解剖结构，完全无牙弓的数字化呈现出局限性。
本临床研究的目的是评估一种新的口内扫描设备，并分析其在捕获无牙下颌弓中种植体的三维（3D）位置方面的有用性。
通过比较 3 种扫描技术，评估了 10 名佩戴固定临时下颌义齿的参与者的 40 个种植体的 3D 位置。在 2 个实验组中生成图像，使用数字扫描体（组 SC）和扫描设备（组 SD），在对照组（组 CT）中，通过实验室扫描从带夹板印模帽获得的模型来获取图像。使用逆向工程软件程序将标准三角测量语言（STL）文件叠加，以测量 3D 坐标系。对种植体线性位移（Δx、Δy 和 Δz）、总 3D 位移（Δx+Δy+Δz）和角度投影（ΔθXY、ΔθXZ 和 ΔθYZ）的变化进行了统计学分析（α=.05）。还测量了种植体之间的距离。使用 Spearman 相关系数（α=.05）来确定 3D 坐标和种植体之间距离之间的相关性。
组 SD 的线性位移值低于组 SC，但除了 #2 号种植体外，这种差异没有统计学意义。总体评估显示，组 SD 的准确性更高，差异有统计学意义。关于角度位移，组 SD 在 3 个投影平面上的角度变化较小。对于种植体之间的距离，仅在“全部”评估中观察到显著差异，其中组 SD 的行为类似于组 CT，而组 SC 表现出最高值（P<.05）。未检测到轴（x、y 和 z）和种植体之间距离之间的相关性。
评估的扫描设备提高了下颌无牙弓中线性、角度位移和种植体之间距离的准确性。
