In the article titled "Comparison of the cytotoxicity of 3D-printed aligners using different post-curing procedures: an in vitro study" by Campobasso Alessandra et al., a critical examination of the study's findings reveals some intriguing insights into the cytotoxicity of 3D-printed aligners. The study primarily focuses on the differences in cytotoxicity between aligners post-cured using two different methods: nitrogen inhibition and air curing, and these findings spark a discussion on the limitations of the Dulbecco test.
The Dulbecco Test: Unveiling Its Limitations
The Dulbecco Modified Eagle's Medium (DMEM) cytotoxicity test is a well-established method in cell biology and toxicology. However, it has inherent limitations, including sensitivity to cell types, duration of exposure, and concentration-dependent effects. These limitations mean that the assay may not fully represent real-world conditions, especially when assessing the cytotoxicity of 3D-printed aligners, a subject of growing interest.
Comparing Nitrogen Inhibition and Air Curing
The study's core comparison revolves around aligners post-cured using two different methods. Aligners cured with nitrogen inhibition showed no cytotoxicity, whereas those cured in air exhibited moderate cytotoxicity. A noteworthy point of contention is the significant difference in the post-curing power between the machines used: 40 watts for Formalabs and a substantial 200 watts for Teraharz Graphy. This difference in power could potentially introduce a bias, as higher post-curing power might influence cytotoxicity results.
The Role of an Oxygen Inhibitor: Glycerin
To enhance the rigor of the study, the introduction of an oxygen inhibitor, such as glycerin, in the testing process could have been considered. Glycerin can create an oxygen-depleted environment, reducing the interference of oxygen during the curing process. This approach could help provide a more comprehensive understanding of the influence of curing conditions on cytotoxicity.
A Call for Standardized Parameters
It's important to acknowledge that the curing conditions for the aligners in this study were not standardized. Formalabs and Teraharz Graphy machines operated under different premises, and the study did not factor in the potential impact of these variations. To draw more conclusive results, future studies could benefit from standardizing parameters, including curing power and the use of oxygen inhibitors.
Conflicts of Interest: Marco Migliorati
Lastly, the article notes a potential conflict of interest involving Marco Migliorati, who is identified as a Graphy educator. Transparency in research is crucial, and any affiliations or potential conflicts of interest should be disclosed to ensure the integrity of the study's findings.
In conclusion, the study by Campobasso Alessandra et al. offers valuable insights into the cytotoxicity of 3D-printed aligners. However, the limitations of the Dulbecco test should also be highlighted in the article, the influence of curing conditions, and the importance of addressing potential conflicts of interest. To advance our understanding of the cytotoxicity of dental materials further, future research should consider these factors and strive for standardized testing parameters.