Roatkanjanaporn Nuttakan, Chavanavesh Janeta, Teekavanich Chutimont
Department of Orthodontics, Faculty of Dentistry, Chulalongkorn University, 34 Henri-Dunant Road, Wangmai, Pathumwan, Bangkok, 10330, Thailand.
BMC Oral Health. 2025 Apr 3;25(1):483. doi: 10.1186/s12903-025-05852-3.
Aligner attachment integrity is important for clear aligner retention and overall treatment efficacy. This study aimed to evaluate the wear volume of clear aligner attachments and the retentive force change of clear aligners over a simulated 24-week insertion/removal period, along with their correlation.
Attachments made from Tetric N-Flow (flowable), Beautifil Injectable X (flowable), or Filtek™ Z350 XT (sculptable) resin composites (n = 6 each) were bonded to the first premolars of maxillary dental resin models. Each model underwent a simulated 3-cycle daily insertion and removal of 12 clear aligners, with each aligner tested for 14 days, using a universal testing machine. Attachment wear volume was quantified through 3D scanning and superimposition. Average daily retentive force of aligners was measured. Data were analyzed using mixed-design ANOVA to evaluate differences in retentive force and wear volume among composites, and Pearson's correlation to assess the relationship between wear and retentive force change. Statistical significance was set at p < 0.05.
Significant attachment wear was observed primarily in gingival regions, without significant differences in wear volume among the three composites. Retentive force decreased significantly from days 1 to 2 and continued to decline until day 14 (p < 0.01), without significant differences in retentive force among aligners nor composite types. No significant correlation was found between attachment wear volume and the retentive force difference between the 1st and 12th aligners.
Despite reductions in attachment volume across all three composites over the 24-week period, no significant change in mean retentive force among aligners was observed. The tested composites demonstrated comparable wear resistance during repeated aligner insertion and removal over 24-week, with stable aligner retentive force, supporting their feasibility for use in clear aligner therapy.
矫治器附件的完整性对于透明矫治器的固位及整体治疗效果至关重要。本研究旨在评估在模拟的24周戴入/取出期间透明矫治器附件的磨损量、透明矫治器固位力的变化及其相关性。
将由Tetric N-Flow（可流动型）、Beautifil Injectable X（可流动型）或Filtek™ Z350 XT（可雕刻型）树脂复合材料制成的附件（每种n = 6）粘结到上颌牙树脂模型的第一前磨牙上。每个模型每天模拟进行3个周期的12副透明矫治器的戴入和取出，每副矫治器测试14天，使用万能试验机。通过三维扫描和叠加对附件磨损量进行量化。测量矫治器的平均每日固位力。使用混合设计方差分析来评估复合材料之间固位力和磨损量的差异，并使用Pearson相关性分析来评估磨损与固位力变化之间的关系。设定统计学显著性水平为p < 0.05。
主要在牙龈区域观察到明显的附件磨损，三种复合材料之间的磨损量无显著差异。固位力在第1天到第2天显著下降，并持续下降直到第14天（p < 0.01），矫治器之间以及复合材料类型之间的固位力无显著差异。未发现附件磨损量与第1副和第12副矫治器之间固位力差异之间存在显著相关性。
尽管在24周期间所有三种复合材料的附件体积均有减少，但未观察到矫治器之间平均固位力有显著变化。在24周内重复进行矫治器的戴入和取出过程中，所测试的复合材料表现出相当的耐磨性，矫治器固位力稳定，支持它们在透明矫治器治疗中使用的可行性。
