ArticleProgress in orthodontics2026
Orthodontic derived microplastics impact macrophage differentiation and homeostasis.
Article in Progress in orthodontics, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers, 1 of them a synthesis that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
6 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Ageing effects on chemical, physical, mechanical, and morphological properties of clear aligners - a systematic review.Progress in orthodontics · 2026Pooled it
- Clear Aligners as a Prescribed Source of Unmeasured Intra-Oral Micro- and Nanoplastic Exposure: Release Mechanisms, Human Evidence, Salivary Biomonitoring and the EU Regulatory Context.Materials (Basel, Switzerland) · 2026Review
- Flexural Stiffness and Force Retention of Six 3D-Printed Thermoplastics for Orthodontic Appliances: An In Vitro Screening Study.Dentistry journal · 2026Article
- Cytotoxicity assessment of LuxCreo and Nylon direct-printed photopolymers for orthodontic applications: An in vitro study.Clinical oral investigations · 2026Article
- Micro/Nanoplastics and Periodontitis: An Environmental Microbiology Perspective on Oral Retention and Systemic Risk.Microorganisms · 2026Review
- Clear aligner therapy among orthodontists in Turkey: practice patterns and comparison with previously reported Iranian findings.Frontiers in dental medicine · 2026Article
Corrections and comments
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Authors and funding
7 authors.
Funding
Abstract
backgroundSynthetic polymers are widely used in medical and dental appliances, including clear aligners, retainers, splints, and sleep devices. Despite their widespread use, little is known about the release of microplastics from traditional thermoformed polymers compared with recently developed direct-printed photopolymers. Plastic particles have been detected in a variety of human tissues such as, lung, liver, spleen and kidneys. Each of these sites contain local resident macrophages tasked with maintaining homeostasis by clearing cell debris and foreign bodies. Like these organs, the oral cavity has an extensive population of macrophages that complete immune surveillance and support oral tissue health. Therefore, orthodontic plastic particles may have profound local and systemic biological impacts. As such, we systematically characterized release and particle structure of several clinical orthodontic polymers and visualized their uptake and impacts on macrophage differentiation.
methodsPolymers were tested with the following compositions, direct-printed resins: ActiveMemory™ DCA (Lux Creo Inc.), Tera Harz TA-28 (Graphy Inc.), Nylon 12 (EOS) and thermoformed materials: Invisacryl™ (Great Lakes Dental Technologies), Zendura
resultsAll materials released detectable particles, with direct-printed polymers producing the highest concentrations. Direct-printed materials shed more micro-sized plastics, whereas thermoformed materials predominantly released nano-sized particles. Macrophages readily phagocytosed plastics about 2-10 μm in size. Co-culture with urethane-based direct-printed materials promoted macrophage differentiation toward M1-like iNOS⁺CD86⁺ subsets associated with pro-inflammatory activity.
conclusionsOur findings reveal that commonly used orthodontic materials release micro- and nano-plastics that are readily taken up by macrophages, with direct-printed polymers releasing higher levels of immunostimulatory particles. The resulting shift toward pro-inflammatory macrophage phenotypes raises concern that material choice could influence not only local oral health but also systemic immune responses. These results underscore the importance of evaluating microplastic release in dental and medical devices to guide safer material selection and minimize unintended biological consequences.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.