Accuracy of orthodontic models prototyped for clear aligners therapy: a 3D imaging analysis comparing different market segments 3D printing protocols

Objectives: This study aimed to evaluate the accuracy of orthodontic models for the production of clear aligners generated with four 3D printers featuring different technologies and belonging to different market segments.Materials and methods: Eighty identical dental models were generated from two master digital files (.stl), respectively with aligned (AM group) and crowded dentition (CM group), and prototyped via four different 3D printers, i.e., Asiga Pro 4K65 (DLP technology, high-professional segment), Elegoo Mars Pro (LCD technology, entry-level segment), Form 3B (SLA technology, medium-professional segment) and Vector 3SP (SLA technology, industrial segment). Each 3D printed model was scanned and superimposed with the master file, and deviation analysis was used to evaluate trueness and precision (root mean square values). All data were statistically analyzed (p < 0.05).Results: The trueness error was lower in models prototyped with SLA printers compared to the LCD/DLP printers (p < 0.001); models prototyped with Elegoo Mars Pro-showed higher precision error compared to the other printers (P < 0.001). The models in the CM group showed higher trueness error compared to AM group when prototyped with LCD/DLP printers (p < 0.001). Accuracy error values were within the accepted clinical error for producing clear aligners (< 0.25 mm), with the entry-level 3D printer almost reaching this value.Conclusion: The accuracy of orthodontic models generated for clear aligners can be influenced by different technologies/market segments of the 3D printers used.