In Vitro Cytotoxicity Assessment of Different Thermoplastic Aligner Materials

  • Acta Stomatol Croat. 2025 Jun;59(2):124-132. doi: 10.15644/asc59/2/2.
Ružica Bandić  1  2 ,  Ivna Vuković Kekez  2  3 ,  Vedrana Čikeš Čulić  4 ,  Ivan Galić  3  5 ,  Gordana Paić Karega  2 ,  Danijela Kalibović Govorko  2  3
Affiliations
  • 1. Department of Research in Biomedicine and Health, University of Split School of Medicine, Split, Croatia.
  • 2. Department of Orthodontics, University of Split School of Medicine, Split, Croatia.
  • 3. Department of Maxillofacial Surgery, University Hospital of Split Križine, Split, Croatia.
  • 4. Department of Medical Chemistry and Biochemistry, University of Split School of Medicine, Split, Croatia.
  • 5. Department of Oral Surgery, University of Split School of Medicine, Split, Croatia.
PMID: 40641583 DOI: 10.15644/asc59/2/2
Abstract

Objectives: This study evaluated the cytotoxicity of different thermoplastic Materials and the impact of thermoforming on their cytotoxicity.

Materials and methods: Four 3D thermoplastic Materials were tested before and after thermoforming: Zendura A (Bay Materials), Zendura FLX (Bay Materials), Erkoloc-pro (Erkodent), and CA Pro + (Scheu Dental). The samples were stored in artificial saliva and incubated at 37 °C for 14 days to simulate conditions in the oral cavity during one stage of clear aligner treatment. Then, the saliva was diluted with a complete culture medium at three concentrations: c1=10%, c2=20% and c3=30%. Cytotoxic activities of the Materials were evaluated after incubation for 4h, 24h, 48h, and 72h by using the CCK-8 assay on human oral fibroblast cells (Innoprot, REF: P10868).

Results: The mean measured values of metabolically active cells below 70% of the control were for c3 of non-thermoformed Zendura A and Erkoloc-pro, and thermoformed Zendura A, after 72-hour incubation. The analysis showed differences between non-thermoformed: Zendura A and Erkoloc-pro and Zendura FLX and CA Pro +, thermoformed: Zendura A and CA Pro +, and Zendura FLX and CA Pro + at certain conditions. Differences between concentrations (c2 vs. c3 and c1 vs. c3) in the non-thermoformed group were found. There were no statistically significant differences in cytotoxicity between non-thermoformed and thermoformed groups.

Conclusions: Cytotoxicity was observed in non-thermoformed and thermoformed Materials, with significant differences between concentrations of the same material. However, the thermoforming process did not impact the cytotoxicity of clear aligner Materials.

Keywords
Biocompatibility; Cell culture; Cytotoxins; Dental materials; Fibroblasts; Long Term Adverse Effects; MeSH Terms: Removable Orthodontic Appliances; Orthodontic appliances; Removable.
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