Orthod Craniofac Res. 2021 Sep 27. doi: 10.1111/ocr.12537. Online ahead of print.
ABSTRACT
OBJECTIVE: Aim of this study was to compare the mechanical properties of orthodontic aligners among different commercially available 3D printing devices.
MATERIALS AND METHODS: Five 3D printers (Ka:rv LP 550, Swinwon; “KAR”), (L120, Dazz 3D; “L12”), (MiiCraft 125, Miicraft Jena; “MIC”), (Slash 2, Uniz; “SLS”) and (Pro 95, SprintRay; “PRO”) were used to prepare orthodontic aligners with dental resin (Tera Harz TC-85DAW, Graphy). The central incisors of each aligner were cut, prepared, and evaluated in terms of Martens-Hardness (HM), indentation-modulus (EIT ), and elastic-index (ηIT ) as per ISO14577-1:2002. Force-indentation curves were recorded and differences among printers were checked with generalized linear regressions (alpha=5%).
RESULTS: Statistically significant differences were seen for all mechanical properties (P<0.05), which were in descending order: HM (N/mm2 ) as median (Interquartile Range [IQR]): SLS 108.5 (106.0-112.0), L12 103.0 (102.0-107.0), KAR 101.5 (97.5-103.0), MIC 100.0 (97.5-101.5), and PRO 94.0 (93.0-96.0); EIT (MPa) as mean (Standard Deviation [SD]): SLS 2696.3 (124.7), L12 2627.8 (73.5), MIC 2566.2 (125.1), KAR 2565.0 (130.2), PRO 2491.2 (53.3); ηIT (%) as median (IQR): SLS 32.8 (32.3-33.1), L12 31.6 (30.8-32.3), KAR 31.3 (30.9-31.9), MIC 30.5 (29.9-31.2), PRO 29.5 (29.1-30.0). Additionally, significant differences existed between Liquid Crystal Display (LCD) and Digital Light Processing (DLP) printers for HM (P<0.001), EIT (P=0.002), and ηIT (P<0.001), with aligners from the former having higher values than aligners from the latter printer.
CONCLUSION: Under the limitations of this study it may be concluded that the mechanical properties of 3D-printed orthodontic aligners are dependent on the 3D printer used and thus differences in their clinical efficacy are anticipated.
PMID:34569692 | DOI:10.1111/ocr.12537
