Iliadi Anna, Koletsi Despina, Papageorgiou Spyridon N, Eliades Theodore
Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, 11527 Athens, Greece.
Clinic of Orthodontics and Pediatric Dentistry, Center of Dental Medicine, University of Zurich, 8032 Zurich, Switzerland.
Materials (Basel). 2020 Apr 14;13(8):1843. doi: 10.3390/ma13081843.
Use of thermoplastic material in orthodontics, either as aligner or as retainer appliances, is common practice and is likely to increase in the years to come. However, no systematic assessment on safety considerations of these adjuncts has been implemented up to date. The aim of this systematic review was to collectively appraise the existing evidence from both clinical and laboratory studies, on whether these appliances are associated with any estrogenic/cytotoxic effects or bisphenol-A (BPA) and monomer leaching. Eight electronic databases were searched with no limits in December 22, 2019, for published and unpublished research. Eligibility criteria comprised of studies of any design, describing use of any type of thermoplastic aligner. Study selection, data extraction and risk of bias (RoB) assessment was done independently, either in duplicate or confirmed by a second reviewer. Random effects meta-analyses of weighted mean differences (WMD) with associated 95% Confidence Intervals (CIs) were planned. Quality of the evidence was evaluated with Grading of Recommendations Assessment, Development and Evaluation (GRADE). A total of 58 articles were initially identified, while 5 were included in qualitative synthesis and 2 of those contributed to the quantitative syntheses. Four studies were in-vitro, while one was a randomized controlled trial; all assessed some type of orthodontic aligner or retainer, either as-received or retrieved. Risk of bias recordings ranged between unclear and high for all studies. Proliferation induction capacity of thermoplastic appliances' eluents on MCF-7 cells failed to be confirmed compared to beta-estradiol (2 studies: 5% /, WMD: -182.08; 95% CI: -198.83, -165.33; -value < 0.001; and 20% /, WMD: -184.53; 95% CI: -206.17, -162.88; -value < 0.001). No cytotoxic activity was detected as well. In addition, although evidence from in-vitro studies was indicative of no traceable detection of BPA or other monomers, the findings from a single clinical trial were allied to increased levels of BPA in whole stimulated saliva, after up to 30 days of thermoplastic retainer usage, compared to standard Hawley retainer. The quality of the evidence overall was low to medium. Current data from in-vitro research are indicative of an absence of an estrogenic or cytotoxic effect of thermoplastic aligners or retainers. Regarding BPA or monomer release, evidence from clinical and laboratory studies appear inconsistent.
在正畸治疗中使用热塑性材料，无论是作为矫治器还是保持器，都是常见的做法，并且在未来几年可能会增加。然而，迄今为止尚未对这些辅助器具的安全性进行系统评估。本系统评价的目的是综合评估临床和实验室研究中的现有证据，以确定这些器具是否与任何雌激素/细胞毒性作用或双酚A（BPA）及单体浸出有关。2019年12月22日，对八个电子数据库进行了无限制检索，以查找已发表和未发表的研究。纳入标准包括任何设计的研究，描述任何类型热塑性矫治器的使用情况。研究选择、数据提取和偏倚风险（RoB）评估均由独立人员进行，可重复操作或由第二位审阅者确认。计划对加权平均差（WMD）及相关95%置信区间（CI）进行随机效应荟萃分析。采用推荐分级评估、制定和评价（GRADE）方法评估证据质量。最初共识别出58篇文章，其中5篇纳入定性综合分析，2篇纳入定量综合分析。四项研究为体外研究，一项为随机对照试验；所有研究均评估了某种类型的正畸矫治器或保持器，包括收到时的或回收的。所有研究的偏倚风险记录在不明确和高之间。与β-雌二醇相比，热塑性器具洗脱液对MCF-7细胞的增殖诱导能力未得到证实（两项研究：5%/，WMD：-182.08；95%CI：-198.83，-165.33；P值<0.001；以及20%/，WMD：-184.53；95%CI：-206.17，-162.88；P值<0.001）。也未检测到细胞毒性活性。此外，尽管体外研究的证据表明未检测到可追踪的BPA或其他单体，但一项临床试验的结果显示，与标准Hawley保持器相比 在使用热塑性保持器长达30天后，全刺激唾液中的BPA水平升高。总体证据质量为低到中等。目前体外研究的数据表明热塑性矫治器或保持器不存在雌激素或细胞毒性作用。关于BPA或单体释放，临床和实验室研究的证据似乎不一致。
