Kim Taehun, Lee Sangwook, Kim Guk Bae, Hong Dayeong, Kwon Jinhee, Park Jae-Woo, Kim Namkug
Graduate student, Department of Biomedical Engineering, Asan Medical Institute of Convergence Science and Technology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
Postdoctoral Researcher, ANYMEDI Inc, Seoul, Republic of Korea.
J Prosthet Dent. 2020 Aug;124(2):195-201.e2. doi: 10.1016/j.prosdent.2019.06.006. Epub 2019 Nov 18.
The accuracy of 3D printing technology is essential for clinical applications. However, depending on the 3D printing method, machine, and environment, the accuracy varies even if the same computer-aided design (CAD) model is printed.
The purpose of this in vitro study was to evaluate the differences between the CAD model and the printed parts with a simplified guide designed based on the implant guide and to compare the accuracy among 3 types of 3D printers.
A maxilla and mandible implant guide made of complex anatomic structures is difficult to measure accurately. For accurate measurements, 16 simplified guides were designed based on the maxilla and mandible implant guide. The 16 simplified guides were fabricated by using the following 3 different 3D printer technologies: photopolymer jetting (PolyJet), stereolithography apparatus (SLA), and multijet printing (MJP). Each simplified guide was measured 4 times with digital calipers for 20 linear measurements. The measured simplified guides were compared with the CAD model, and the accuracy of the 3D printers was compared. The mean absolute difference and mean relative difference were calculated, and the Bland-Altman analysis was used to evaluate the limits of agreement between the CAD model and the printed parts. The Wilcoxon signed-rank test was performed to evaluate the significant differences among the 3D printers (α=.05).
The mean absolute difference and the mean relative difference between the CAD model and the 3D-printed parts were 0.06 ±0.05 mm (0.46 ±0.51%) for PolyJet, 0.09 ±0.05 mm (0.66 ±0.62%) for SLA, and 0.31 ±0.33 mm (1.11 ±0.70%) for MJP. When the 3D printers were compared, significant differences were found between SLA and MJP (P=.006) and between PolyJet and MJP (P=.001).
When the CAD models and the 3D-printed parts of the simplified implant guides were compared, significant accuracy differences were observed. The PolyJet and SLA 3D printers met the required accuracy for clinical applications in dentistry. The most suitable 3D printer, however, should be selected considering all factors.
3D打印技术的精度对于临床应用至关重要。然而，根据3D打印方法、机器和环境的不同，即使打印相同的计算机辅助设计（CAD）模型，精度也会有所差异。
本体外研究的目的是评估基于种植体导板设计的简化导板的CAD模型与打印部件之间的差异，并比较3种类型3D打印机的精度。
由复杂解剖结构制成的上颌和下颌种植体导板难以精确测量。为了进行精确测量，基于上颌和下颌种植体导板设计了16个简化导板。使用以下3种不同的3D打印技术制造这16个简化导板：光聚合物喷射（PolyJet）、立体光刻设备（SLA）和多喷射打印（MJP）。每个简化导板用数字卡尺测量4次，进行20次线性测量。将测量的简化导板与CAD模型进行比较，并比较3D打印机的精度。计算平均绝对差和平均相对差，并使用Bland-Altman分析评估CAD模型与打印部件之间的一致性界限。进行Wilcoxon符号秩检验以评估3D打印机之间的显著差异（α=0.05）。
CAD模型与3D打印部件之间的平均绝对差和平均相对差分别为：PolyJet为0.06±0.05mm（0.46±0.51%），SLA为0.09±0.05mm（0.66±0.62%），MJP为0.31±0.33mm（1.11±0.70%）。比较3D打印机时，发现SLA与MJP之间（P=0.006）以及PolyJet与MJP之间（P=0.001）存在显著差异。
比较简化种植体导板的CAD模型和3D打印部件时，观察到显著的精度差异。PolyJet和SLA 3D打印机满足牙科临床应用所需的精度。然而，应综合考虑所有因素来选择最合适的3D打印机。
