PhD student, Department of Occlusion, Fixed Prosthesis and Dental Materials, School of Dentistry, Federal University of Uberlândia, Uberlândia, MG, Brazil.
Private practice, São Paulo, Brazil.
J Prosthet Dent. 2023 Feb;129(2):350-353. doi: 10.1016/j.prosdent.2021.06.006. Epub 2021 Jul 1.
When 3-dimensional printing casts, the operator can change the type of resin and the printing layer thickness, reducing the fabrication time. However, how these parameters affect the accuracy of 3-dimensionally printed casts is unknown.
The purpose of this in vitro study was to evaluate the accuracy of 3-dimensionally printed casts by using a stereolithography (SLA) 3-dimensional printer (Forms2) with 3 different layer thickness (25, 50, and 100 μm) and 2 different resins (Gray and Cast) and by comparing the time to obtain each cast.
One master cast was scanned, and a single file was printed several times. The printed casts were then scanned by using a laboratory scanner. The standard tessellation language (STL) files provided by the laboratory scanner were superimposed and compared by using a software program (Geomagic Control; 3D Systems). The 2-way ANOVA test was used for the trueness evaluation, followed by the Tukey test to identify differences among the groups (α=.05).
No statistically significant differences in accuracy were found among the 3 different layers for either resin (P>.05). Printing time doubled as layer thickness decreased.
This study showed that when printing casts, the fastest printing settings can be used without losing accuracy and that the laboratory digital workflow can be accelerated with selection of the resin and cast layer, as the type of resin and layer thickness did not influence the quality of the casts.
当使用立体光固化（SLA）3D 打印机（Forms2）进行 3D 打印时，操作人员可以改变树脂类型和打印层厚度，从而缩短制造时间。然而，这些参数如何影响 3D 打印模型的准确性尚不清楚。
本体外研究的目的是通过使用具有 3 种不同层厚（25、50 和 100μm）和 2 种不同树脂（Gray 和 Cast）的立体光固化（SLA）3D 打印机（Forms2）来评估 3D 打印模型的准确性，并比较获得每个模型的时间。
扫描一个主模型，并多次打印单个文件。然后使用实验室扫描仪扫描打印的模型。使用软件程序（Geomagic Control；3D Systems）将实验室扫描仪提供的标准 tessellation language（STL）文件进行叠加和比较。使用双向方差分析（ANOVA）检验进行准确性评估，然后使用 Tukey 检验来确定组间差异（α=.05）。
对于两种树脂，不同层厚之间的准确性均无统计学差异（P>.05）。随着层厚的减小，打印时间增加了一倍。
本研究表明，在打印模型时，可以使用最快的打印设置而不会降低准确性，并且可以通过选择树脂和模型层来加速实验室数字化工作流程，因为树脂类型和层厚不会影响模型的质量。
