Süpple Julia, von Glasenapp Julius, Hofmann Eva, Jost-Brinkmann Paul-Georg, Koch Petra Julia
Department of Orthodontics, Dentofacial Orthopedics and Pedodontics, Charité Center for Oral Health Sciences CC3, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Aßmannshauser Straße 4-6, 14197 Berlin, Germany.
J Clin Med. 2021 May 7;10(9):2002. doi: 10.3390/jcm10092002.
A digital workflow opens up new possibilities for the indirect bonding (IDB) of brackets. We tested if the printing orientation for bracket transfer models on the build platform of a 3D printer influences the accuracy of the following IDB method. We also evaluated the clinical acceptability of the IDB method combining digitally planned and printed transfer models with the conventional fabrication of pressure-molded transfer trays.
In total, 27 digitally planned bracket transfer models were printed with both 15° and 75° angulation from horizontal plane on the build platform of a digital light processing (DLP) printer. Brackets were temporarily bonded to the transfer models and pressure-molded trays were produced on them. IDB was then performed using the trays on the respective plaster models. The plaster models were scanned with an optical scanner. Digitally planned pre-bonding and scanned post-bonding bracket positions were superimposed with a software and resulted in three linear and three angular deviations per bracket.
No statistically significant differences of the transfer accuracy of printed transfer models angulated 15° or 75° on the 3D printer build platform were found. About 97% of the linear and 82% of the angular deviations were within the clinically acceptable range of ±0.2 mm and ±1°, respectively. The highest inaccuracies in the linear dimension occurred in the vertical towards the gingival direction and in the angular dimension in palatal crown torque.
For the IDB method used, the printing orientation on the build platform did not have a significant impact on the transfer accuracy.
数字化工作流程为托槽间接粘接（IDB）带来了新的可能性。我们测试了3D打印机构建平台上托槽转移模型的打印方向是否会影响后续IDB方法的准确性。我们还评估了将数字化规划和打印的转移模型与传统制作的压膜转移托盘相结合的IDB方法的临床可接受性。
总共27个数字化规划的托槽转移模型在数字光处理（DLP）打印机的构建平台上以与水平面成15°和75°的角度进行打印。托槽临时粘接在转移模型上，并在其上制作压膜托盘。然后使用这些托盘在相应的石膏模型上进行IDB。用光学扫描仪对石膏模型进行扫描。通过软件将数字化规划的粘接前和扫描后的托槽位置进行叠加，每个托槽产生三个线性偏差和三个角度偏差。
在3D打印机构建平台上，打印角度为15°或75°的转移模型的转移精度没有统计学上的显著差异。约97%的线性偏差和82%的角度偏差分别在临床可接受的±0.2mm和±1°范围内。线性尺寸上的最大误差出现在向牙龈方向的垂直方向，角度尺寸上的最大误差出现在腭侧冠转矩方面。
对于所使用的IDB方法，构建平台上的打印方向对转移精度没有显著影响。
