Joda Tim, Matthisson Lea, Zitzmann Nicola U
Department of Reconstructive Dentistry, University Center for Dental Medicine Basel, University of Basel, 4058 Basel, Switzerland.
J Clin Med. 2020 May 12;9(5):1436. doi: 10.3390/jcm9051436.
The aim of this in vitro study was to analyze the impact of model aging on the accuracy of 3D-printed dental models. A maxillary full-arch reference model with prepared teeth for a three-unit fixed dental prosthesis was scanned ten times with an intraoral scanner (3Shape TRIOS Pod) and ten models were 3D printed (Straumann P-Series). All models were stored under constant conditions and digitized with a desktop scanner after 1 day; 1 week; and 2, 3, and 4 weeks. For accuracy, a best-fit algorithm was used to analyze the deviations of the abutment teeth (GFaI e.V Final Surface). were used for comparisons with the level of significance set at α = 0.05. Deviation analysis of the tested models showed homogenous intragroup distance calculations at each timepoint. The most accurate result was for 1 day of aging (3.3 ± 1.3 µm). A continuous decrease in accuracy was observed with each aging stage from day 1 to week 4. A time-dependent difference was statistically significant after 3 weeks ( = 0.0008) and 4 weeks ( < 0.0001). Based on these findings, dental models should not be used longer than 3 to 4 weeks after 3D printing for the fabrication of definitive prosthetic reconstructions.
这项体外研究的目的是分析模型老化对3D打印牙科模型准确性的影响。使用口腔内扫描仪（3Shape TRIOS Pod）对上颌全牙弓参考模型（已为三单位固定义齿制备好牙齿）进行了10次扫描，并3D打印了10个模型（士卓曼P系列）。所有模型均在恒定条件下保存，并在1天、1周以及2、3和4周后使用桌面扫描仪进行数字化处理。为了评估准确性，使用了最佳拟合算法来分析基牙（德国牙科技术协会最终表面）的偏差。使用α = 0.05的显著性水平进行比较。测试模型的偏差分析显示，在每个时间点组内距离计算均具有同质性。老化1天时的结果最准确（3.3±1.3 µm）。从第1天到第4周，随着每个老化阶段的推进，准确性持续下降。在3周（P = 0.0008）和4周（P < 0.0001）后，时间依赖性差异具有统计学意义。基于这些发现，3D打印后的牙科模型用于制作最终修复体时，使用时间不应超过3至4周。
