Brandão Nathália Moraes Carvalho Barreto, Maia Raiane Machado, Gomes Victor de Morais, Resende Carolina, Antunes Alberto Nogueira da Gama, Souki Bernardo Quiroga
Pontifical Catholic University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Department of Dentistry, Pontifical Catholic University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Orthod Craniofac Res. 2024 Dec;27 Suppl 2:120-130. doi: 10.1111/ocr.12843. Epub 2024 Aug 8.
To evaluate the 3D accuracy of attachment positioning and the adaptation of aligners to attachments using in-house templates made with either polyethylene terephthalate glycol (PETG) or ethylene-vinyl acetate (EVA) and either pressure or vacuum thermoforming machines.
Overall, 140 test specimens were resin-printed. Templates for the attachment bonding were made with 1-mm EVA or 0.5-mm PETG laminates. Orthodontic aligners were manufactured with 0.75-mm PETG. The thermoplastification process was carried out using either vacuum or pressure machines. The positional differences between the virtual and bonded attachments were assessed in the X, Y and Z coordinates. The marginal adaptation between the aligners and the attachments was measured.
Minor inaccuracies in the positioning of the attachments were observed in all combinations of thermoforming machines and plastic laminates used to fabricate the templates, mainly in the superior-inferior (Z) dimension. PETG performed better than EVA in the anterior region (p < .05). No association was found between thermoplastification machines and the accuracy of the positioning of the attachments (p > .05). While small misadaptations between the aligners and the attachments were observed, the EVA templates performed better than the PETG templates.
The inaccuracy of the attachment positioning and the misadaptation of the aligners to the attachments were slight. The vacuum and pressure thermoplastification machines showed no difference in attachment positioning accuracy. The PETG template was better than the EVA template in the anterior region, but the EVA attachments presented a better adaptation to the aligners than the PETG attachments.
使用由聚对苯二甲酸乙二醇酯二醇（PETG）或乙烯-醋酸乙烯酯（EVA）制成的内部模板以及压力或真空热成型机，评估附着体定位的三维精度以及矫治器与附着体的贴合度。
总共树脂打印了140个测试样本。用于附着体粘结的模板由1毫米厚的EVA或0.5毫米厚的PETG层压板制成。正畸矫治器由0.75毫米厚的PETG制造。热塑成型过程使用真空或压力机进行。评估虚拟附着体和粘结附着体在X、Y和Z坐标上的位置差异。测量矫治器与附着体之间的边缘贴合度。
在用于制造模板的热成型机和塑料层压板的所有组合中，均观察到附着体定位存在微小误差，主要在上下（Z）维度。PETG在前牙区的表现优于EVA（p < 0.05）。未发现热塑成型机与附着体定位精度之间存在关联（p > 0.05）。虽然观察到矫治器与附着体之间存在小的贴合不良，但EVA模板的表现优于PETG模板。
附着体定位的误差和矫治器与附着体的贴合不良较小。真空和压力热塑成型机在附着体定位精度上没有差异。PETG模板在前牙区优于EVA模板，但EVA附着体比PETG附着体与矫治器的贴合度更好。
