Biocompatibility of direct printed clear aligners: A systematic review of in vitro studies

IF 1.8 Q2 DENTISTRY, ORAL SURGERY & MEDICINE

International Orthodontics Pub Date : 2025-05-28 DOI:10.1016/j.ortho.2025.101028

Claire-Adeline Dantagnan , Sylvie Babajko , Ali Nassif , André Porporatti , Jean-Pierre Attal , Elisabeth Dursun , Jean-François Nguyen , Julia Bosco

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引用次数: 0

Abstract

Objective

Three-dimensional printing of aligners has gained in popularity as an alternative to thermoformed aligners. Only few studies evaluate the biological effects of these new materials. This systematic review aims to investigate the residual monomers leaching from direct printed clear aligners and their possible toxic effects.

Search methods

A search was conducted on several databases in accordance with PRISMA guidelines. In vitro, in vivo and clinical studies in English were included. The risk of bias of in vitro studies was assessed by QUIN Tool, for in vivo studies with the SYRCLE tool and for clinical studies with the RoB-2 tool.

Results

In all, 524 articles were initially identified and nine were included in the qualitative analysis. All the included studies were in vitro research with a moderate risk of bias. Seven studies were focused on cell toxicity and two on monomer release. Although mixed results are described, 3D printed aligners could present a slight cytotoxicity. Compared with thermoformed aligners, direct printed aligners had higher cytotoxicity levels. No estrogenic effects and no trace of Bisphenol A (BPA) release were detected from printed aligners when investigated but a leaching of Urethane Dimethacrylate (UDMA) have been reported in all studies. Post-curing was an important step to obtain satisfactory biocompatibility of printed aligners.

Conclusions

There is no consensus on the absence of cytotoxic effects of direct printed aligners but the release of some potentially active monomers including UDMA requires further investigations on long-term effects on patients’ health.

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直接印刷透明对准器的生物相容性：体外研究的系统回顾

目的三维打印矫形器作为热成型矫形器的一种替代方法已经越来越受欢迎。只有少数研究评估了这些新材料的生物学效应。本系统综述旨在探讨直接印刷透明对准剂的残留单体浸出及其可能的毒性作用。检索方法按照PRISMA指南对几个数据库进行了检索。包括体外、体内和临床英文研究。体外研究的偏倚风险采用QUIN工具评估，体内研究采用sycle工具评估，临床研究采用rob2工具评估。结果共筛选到524篇文献，其中9篇纳入定性分析。所有纳入的研究均为具有中等偏倚风险的体外研究。其中7项研究关注细胞毒性，2项研究关注单体释放。虽然描述了不同的结果，但3D打印的对准器可能呈现轻微的细胞毒性。与热成型矫形剂相比，直接打印矫形剂具有更高的细胞毒性水平。在调查时，没有从印刷的校准器中检测到雌激素效应和双酚A （BPA）释放的痕迹，但在所有研究中都报告了二甲基丙烯酸乙酯（UDMA）的浸出。后固化是获得良好生物相容性的重要步骤。结论：对于直接打印的校正剂没有细胞毒性作用尚无共识，但包括UDMA在内的一些潜在活性单体的释放需要进一步研究对患者健康的长期影响。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

International Orthodontics DENTISTRY, ORAL SURGERY & MEDICINE-

CiteScore

2.50

自引率

13.30%

发文量

审稿时长

26 days

期刊介绍： Une revue de référence dans le domaine de orthodontie et des disciplines frontières Your reference in dentofacial orthopedics International Orthodontics adresse aux orthodontistes, aux dentistes, aux stomatologistes, aux chirurgiens maxillo-faciaux et aux plasticiens de la face, ainsi quà leurs assistant(e)s. International Orthodontics is addressed to orthodontists, dentists, stomatologists, maxillofacial surgeons and facial plastic surgeons, as well as their assistants.