National Dental Centre Singapore, 5Second Hospital Ave, 168938 Singapore.
National University, Centre for Oral Health Singapore 9 Lower Kent Ridge Road, 119085 Singapore.
J Dent. 2022 Feb;117:103908. doi: 10.1016/j.jdent.2021.103908. Epub 2021 Nov 29.
The primary aim of this study was to assess the linear and geometric accuracy of 3-dimensional (3D) printed tooth replicas when compared to the actual tooth. The secondary aims were to compare the accuracy of three different 3D printers and to evaluate dimensional changes of tooth replicas after sterilization.
A sample of 16 teeth were selected from recruited patients. Segmentation was carried out to generate files from the patient's cone beam computed tomography (CBCT) data, Tooth replicas were then printed using three printers making use of Polyjet, laser stereolithography (SLA) and digital light processing (DLP) technology respectively. These replicas, along with the actual tooth, were scanned by an optical scanner. Replicas were sent for sterilization and scanned again. Paired superimposition of the scans was performed.
A mean length difference of 0.36 mm and mean geometric (root mean square [RMS]) difference of 0.56 mm was found. Qualitative analysis showed that the replicas were generally larger in size. Repeated ANOVA tests showed that the Polyjet printer had the highest accuracy (p<0.0001). After sterilization, there was an overall mean length difference of 0.10 mm and RMS deviation of 0.02 mm.
This study found that there was a significant difference in linear and geometric measurements of the tooth replicas when compared to the actual tooth. This study also provides evidence that the printer which made use of Polyjet technology was able to produce more accurate models than SLA or DLP printers. Printed tooth models demonstrated clinically insignificant changes after heat sterilization.
3D printed tooth replicas derived from the patient's CBCT data may be used in autotransplantation to increase predictability of the procedure. In order for this novel digital approach to realize its potential, it is critical to address questions as to how accurate the various printing technologies are in fabricating replicas.
本研究的主要目的是评估 3 维（3D）打印牙复制体与实际牙相比的线性和几何精度。次要目的是比较三种不同 3D 打印机的精度，并评估牙复制体在消毒后的尺寸变化。
从招募的患者中选择了 16 颗牙齿作为样本。进行分割以从患者的锥形束计算机断层扫描（CBCT）数据中生成文件，然后分别使用 Polyjet、激光立体光刻（SLA）和数字光处理（DLP）技术的三台打印机打印牙复制体。这些复制体与实际牙齿一起通过光学扫描仪进行扫描。将复制体送去消毒并再次扫描。执行扫描的配对叠加。
发现平均长度差异为 0.36mm，平均几何（均方根[RMS]）差异为 0.56mm。定性分析表明，复制体的尺寸通常较大。重复方差分析检验表明，Polyjet 打印机的精度最高（p<0.0001）。消毒后，整体平均长度差异为 0.10mm，RMS 偏差为 0.02mm。
本研究发现，与实际牙齿相比，牙复制体的线性和几何测量存在显著差异。本研究还提供了证据，表明使用 Polyjet 技术的打印机能够比 SLA 或 DLP 打印机生产更精确的模型。经过热消毒后，打印的牙模型显示出临床意义不大的变化。
从患者的 CBCT 数据中获得的 3D 打印牙复制体可用于自体移植，以提高手术的可预测性。为了使这种新的数字方法实现其潜力，关键是要解决各种打印技术在制造复制体方面的精确性问题。
