Lo I-Lin, Kao Chuan-Yi, Huang Tsui-Hsein, Ho Chun-Te, Kao Chia-Tze
School of Dentistry, Chung Shan Medical University, Taichung, Taiwan.
Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan.
J Dent Sci. 2024 Oct;19(4):2065-2073. doi: 10.1016/j.jds.2024.05.025. Epub 2024 May 31.
BACKGROUND/PURPOSE: Invisible orthodontic treatments are becoming increasingly popular, and numerous brands of invisible aligners are now available. However, concerns remain about the safety of the materials used in these products. This study aimed to assess the cytotoxic effects of both original and thermoformed thermoplastic materials used in orthodontic aligners on human periodontal ligament (HPDL) cells in vitro.
The experiment used six different brands, each containing three types of thermoplastic materials, Polyethylene terephthalateco-1, 4-cyclohexylenedimethylene terephthalate (PETG), thermoplastic polyurethane (TPU), and copolyester polyethylene terephthalate (PET). The original sheets and the thermoformed materials were soaked in a culture medium for seven and fourteen days, and then applied to cultured human periodontal ligament cells. Cells were harvested on the first, third, and fifth days after application, and their viability was analyzed using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay.
The findings revealed that some thermoformed materials, notably PETG, exhibited lower survival rates compared to their non-thermoformed versions. However, other materials such as TP and PET maintained over 70% cell viability, indicating only minor cytotoxic effects.
These findings highlight the need for further research into the long-term biocompatibility of these materials but generally affirm their safety for use in orthodontic aligners under the tested conditions.
背景/目的：隐形正畸治疗越来越受欢迎，现在有众多品牌的隐形矫治器可供选择。然而，人们对这些产品中使用的材料的安全性仍存在担忧。本研究旨在评估正畸矫治器中使用的原始热塑性材料和热成型热塑性材料对人牙周膜（HPDL）细胞的体外细胞毒性作用。
实验使用了六个不同品牌，每个品牌包含三种热塑性材料，聚对苯二甲酸乙二酯-1,4-环己烷二甲醇酯（PETG）、热塑性聚氨酯（TPU）和聚对苯二甲酸乙二酯共聚酯（PET）。将原始片材和热成型材料在培养基中浸泡7天和14天，然后应用于培养的人牙周膜细胞。在应用后的第1、3和5天收获细胞，并使用MTT [3-(4,5-二甲基噻唑-2-基)-2,5-二苯基溴化四氮唑] 法分析其活力。
研究结果显示，一些热成型材料，尤其是PETG，与其未热成型的版本相比，存活率较低。然而，其他材料如TP和PET保持了超过70%的细胞活力，表明只有轻微的细胞毒性作用。
这些发现凸显了对这些材料的长期生物相容性进行进一步研究的必要性，但总体上肯定了它们在测试条件下用于正畸矫治器的安全性。
