Assistant Lecturer, Department of Prosthodontics, Faculty of Dentistry, El-Zagazig University, Zagazig, Sharqia Governorate, Egypt; and PhD Researcher, Department of Prosthodontics, Faculty of Dentistry, Alexandria University, Bab Sharqi, Alexandria Governorate, Egypt.
Professor and Chairman, Department of Prosthodontics, Faculty of Dentistry, Alexandria University, Bab Sharqi, Alexandria Governorate, Egypt.
J Prosthet Dent. 2023 Aug;130(2):252.e1-252.e8. doi: 10.1016/j.prosdent.2023.05.032. Epub 2023 Jul 18.
Digital scanning of different prosthodontic materials is commonplace in contemporary practice. However, the scannability of prosthodontic materials has not been thoroughly investigated.
The purpose of this in vitro study was to evaluate the scanning accuracy and measure the unscanned area in a preset time limit of commonly used framework materials.
A mandibular acrylic resin reference dental typodont with 3 teeth, with the central one prepared for a complete coverage crown, was digitized by using a desktop scanner. A complete coverage crown was generated in standard tessellation language (STL) format. Three groups were created from the digital design according to the crown material: milled polyetheretherketone (PEEK), milled airborne-particle abraded titanium, and milled polymethylmethacrylate (PMMA). They were scanned with the desktop scanner to be used as reference files for each group. The intraoral scanner Medit i700 was used to digitize each specimen 10 times (n=10). Using a nonmetrology grade software program, the deviations between the test STL file of the intraoral scanner and the reference STL file of the desktop scanner were assessed by using the RMS values. The unscanned surface area in a preset time limit of 6 seconds (scannability) was assessed. Groups were compared by using 1-way ANOVA followed by the Tukey post hoc test with Bonferroni correction when the results were significant. All tests were 2-tailed (α=0.05).
Regarding deviation analysis, RMS discrepancies were computed, and significant differences in trueness were found (P<.001) among the 3 studied groups. The titanium group had the highest trueness followed by the PEEK and PMMA groups, which were statistically similar (P>.05). Precision differed significantly among the 3 studied groups (P<.001). PEEK was the most precisely scanned material followed by titanium, and the PMMA group had the least precision. Regarding scannability, there were overall significant differences (P<.001). Titanium was the most scannable, followed by PEEK and then PMMA.
Airborne-particle abraded titanium had better trueness and scannability than PEEK and PMMA. However, PEEK was the most precisely scanned material.
在当代实践中，对不同的修复体材料进行数字扫描已很常见。然而，修复体材料的可扫描性尚未得到彻底研究。
本体外研究的目的是评估常用支架材料的扫描准确性，并测量在预设时间限制内的未扫描区域。
使用桌面扫描仪对带有 3 颗牙齿的下颌丙烯酸树脂参考牙列模型进行数字化，其中中央一颗牙预备用于全冠覆盖。以标准 tessellation language（STL）格式生成全冠。根据冠材料将数字设计分为 3 组：铣削聚醚醚酮（PEEK）、铣削气载颗粒磨损钛和铣削聚甲基丙烯酸甲酯（PMMA）。使用桌面扫描仪对每组进行扫描，作为参考文件。使用 Medit i700 口内扫描仪对每个标本进行 10 次数字化（n=10）。使用非计量级软件程序，通过均方根（RMS）值评估口内扫描仪的测试 STL 文件与桌面扫描仪的参考 STL 文件之间的偏差。在预设的 6 秒时间限制内（可扫描性）评估未扫描的表面积。当结果具有统计学意义时，使用单向方差分析（ANOVA）并随后使用 Tukey 事后检验和 Bonferroni 校正进行组间比较。所有检验均为双侧检验（α=0.05）。
关于偏差分析，计算了均方根差异，并发现 3 个研究组之间的准确性存在显著差异（P<.001）。钛组的准确性最高，其次是 PEEK 组和 PMMA 组，统计学上无差异（P>.05）。3 个研究组之间的精密度存在显著差异（P<.001）。PEEK 是最精确扫描的材料，其次是钛，而 PMMA 组的精度最低。关于可扫描性，总体上存在显著差异（P<.001）。钛最易扫描，其次是 PEEK，然后是 PMMA。
气载颗粒磨损钛的准确性和可扫描性优于 PEEK 和 PMMA。然而，PEEK 是最精确扫描的材料。
