Precision values.

This in-vitro study was designed to investigate whether conventionally produced casts and printed casts for orthodontic purposes show comparable full-arch accuracy. To produce casts, either a conventional impression or a digital data set is needed. A fully dentate all ceramic master cast was digitized with an industrial scanner to obtain a digital reference cast [REF]. Intraoral scans [IOS] and alginate impressions were taken from the master cast so that ten printed and ten gypsum casts were obtained. The printed casts [DLP] were digitized by an industrial scanner and as well as the gypsum casts [GYPSUM]. The following absolute mean trueness evaluations by superimposition were accomplished: [REF vs. GYPSUM]; [REF vs. DLP]; [REF vs. IOS]; [IOS vs. DLP]. For precision analysis the data sets of [GYPSUM], [IOS] and [DLP] were available. The absolute mean trueness values were 68 μm ± 15 μm for [REF vs. GYPSUM], 46 μm ± 4 μm for [REF vs. DLP], 20 μm ± 2 μm for [REF vs. IOS] and 41 μm ± 4 μm for [IOS vs. DLP]. [REF vs. GYPSUM] and [REF vs. DLP], [REF vs. IOS], [REF vs. DLP] and [IOS vs. DLP] showed statistically significant differences. The precision values were 56 μm ± 17 μm for [GYPSUM], 25 μm ± 9 μm for [DLP] and 12 μm ± 2 μm for [IOS] and differed significantly among each other. In the present study the print workflow revealed superior results in comparison to the conventional workflow. Due to contrary deviations in the [REF vs. IOS] and the [IOS vs. DLP] data sets the overall trueness deviations was enhanced.

本体外（in-vitro）研究旨在探究正畸用途的传统翻制模型与3D打印模型是否具备可比的全牙弓精度。模型制作需依赖传统印模或数字数据集。本研究通过工业扫描仪对全牙列全瓷主模型进行数字化处理，以获得数字参考模型（REF）。从该主模型获取口内扫描（Intraoral scans [IOS]）与藻酸盐印模，据此分别制作10个DLP打印模型与10个石膏模型（GYPSUM）。采用工业扫描仪对DLP打印模型与石膏模型均进行了数字化处理。通过重叠配准（superimposition）完成以下绝对平均真实度评估：REF vs. GYPSUM、REF vs. DLP、REF vs. IOS、IOS vs. DLP。精密度分析可使用石膏模型、口内扫描与DLP打印模型的数据集。各配对的绝对平均真实度值分别为：REF vs. GYPSUM组68μm±15μm，REF vs. DLP组46μm±4μm，REF vs. IOS组20μm±2μm，IOS vs. DLP组41μm±4μm。REF vs. GYPSUM、REF vs. DLP、REF vs. IOS及IOS vs. DLP各组间均存在统计学显著差异。各组精密度值分别为：石膏模型组56μm±17μm，DLP打印模型组25μm±9μm，口内扫描组12μm±2μm，且各组间精密度差异均具有统计学意义。本研究中，3D打印工作流程的效果优于传统翻制工作流程。由于REF vs. IOS与IOS vs. DLP数据集的偏差方向相反，整体真实度偏差被放大。