{"title":"Effect of nitrogen atmosphere during 3D printing on mechanical properties of orthodontic aligners.","authors":"Spiros Zinelis, Nearchos Panayi, Georgios Polychronis, Dimitrios Dionysopoulos, Spyridon N Papageorgiou, Theodore Eliades","doi":"10.1111/eos.70008","DOIUrl":null,"url":null,"abstract":"<p><p>The aim of this study was to investigate the effect of low oxygen environment during printing on the mechanical properties of 3D printed aligners. Thirty-six 3D printed rectangular (20 × 20 × 10 mm) specimens were fabricated using the SprintRay Pro 55 printer and equally divided into two groups. Eighteen of them were built under normal atmosphere conditions during printing (CON) and the rest by continuously purging pure (NIT), thereby eliminating the oxygen content. Both groups underwent post-curing in an illuminated chamber. Three samples from each group were analyzed by attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR). The remaining specimens underwent metallographic grinding/polishing followed by nano-indentation testing. The mechanical properties measured were: Martens Hardness (HM), indentation modulus (E<sub>IT</sub>), and elastic index (η<sub>IT</sub>). Statistically significant differences between groups were assessed using Mann-Whitney tests (α = 0.05). Both groups showed identical ATR-FTIR spectra and complete C = C conversion. No statistically significant differences in the parameters tested were seen. The medians (interquartile ranges) were HM CON: 68.0 N/mm<sup>2</sup> (65.0-71.0 N/mm<sup>2</sup>), NIT: 73.0 N/mm<sup>2</sup> (67.0-83.0 N/mm<sup>2</sup>); E<sub>IT</sub> CON: 1999.0 MPa (1952.0-2154.0 MPa); NIT: 2047.0 MPa (1702.0-2104.0 MPa); η<sub>IT</sub> CON: 28.0% (27.2%-29.0%) and NIT: 28.9% (27.1%-31.4%). The results of this study showed that elimination of oxygen during printing does not affect the mechanical properties of 3D printed aligners.</p>","PeriodicalId":11983,"journal":{"name":"European Journal of Oral Sciences","volume":" ","pages":"e70008"},"PeriodicalIF":1.8000,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"European Journal of Oral Sciences","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1111/eos.70008","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"DENTISTRY, ORAL SURGERY & MEDICINE","Score":null,"Total":0}
引用次数: 0
Abstract
The aim of this study was to investigate the effect of low oxygen environment during printing on the mechanical properties of 3D printed aligners. Thirty-six 3D printed rectangular (20 × 20 × 10 mm) specimens were fabricated using the SprintRay Pro 55 printer and equally divided into two groups. Eighteen of them were built under normal atmosphere conditions during printing (CON) and the rest by continuously purging pure (NIT), thereby eliminating the oxygen content. Both groups underwent post-curing in an illuminated chamber. Three samples from each group were analyzed by attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR). The remaining specimens underwent metallographic grinding/polishing followed by nano-indentation testing. The mechanical properties measured were: Martens Hardness (HM), indentation modulus (EIT), and elastic index (ηIT). Statistically significant differences between groups were assessed using Mann-Whitney tests (α = 0.05). Both groups showed identical ATR-FTIR spectra and complete C = C conversion. No statistically significant differences in the parameters tested were seen. The medians (interquartile ranges) were HM CON: 68.0 N/mm2 (65.0-71.0 N/mm2), NIT: 73.0 N/mm2 (67.0-83.0 N/mm2); EIT CON: 1999.0 MPa (1952.0-2154.0 MPa); NIT: 2047.0 MPa (1702.0-2104.0 MPa); ηIT CON: 28.0% (27.2%-29.0%) and NIT: 28.9% (27.1%-31.4%). The results of this study showed that elimination of oxygen during printing does not affect the mechanical properties of 3D printed aligners.
期刊介绍:
The European Journal of Oral Sciences is an international journal which publishes original research papers within clinical dentistry, on all basic science aspects of structure, chemistry, developmental biology, physiology and pathology of relevant tissues, as well as on microbiology, biomaterials and the behavioural sciences as they relate to dentistry. In general, analytical studies are preferred to descriptive ones. Reviews, Short Communications and Letters to the Editor will also be considered for publication.
The journal is published bimonthly.