The korean journal of orthodontics (대한치과교정학회지)

The Korean Association Of Orthodontists (대한치과교정학회)
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Micro-computed tomography evaluation of general trends in aligner thickness and gap width after thermoforming procedures involving six commercial clear aligners: An in vitro study

  • Palone, Mario (Postgraduate School of Orthodontics, University of Ferrara) ;
  • Longo, Mattia (Postgraduate School of Orthodontics, University of Ferrara) ;
  • Arveda, Niki (Postgraduate School of Orthodontics, University of Ferrara) ;
  • Nacucchi, Michele (Division for Sustainable Materials, Research Centre of Brindisi) ;
  • De Pascalis, Fabio (Division for Sustainable Materials, Research Centre of Brindisi) ;
  • Spedicato, Giorgio Alfredo (School of Economics, Management and Statistics, University of Bologna) ;
  • Siciliani, Giuseppe (Department of Translational Medicine and for Romagna, School of Dentistry, University of Ferrara) ;
  • Lombardo, Luca (Postgraduate School of Orthodontics, University of Ferrara)
  • Received : 2020.05.13
  • Accepted : 2020.12.09
  • Published : 2021.03.25
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Abstract

Objective: To assess the effects of thermoforming on aligner thickness and gap width in six aligner systems with the same nominal thickness. Methods: Six passive upper aligners of different brands were adapted to a single printed cast. Each sample was evaluated with high-resolution micro-computed tomography. To investigate aligner thickness and gap width, two-dimensional (2D) analysis was conducted assessing the effects of the following variables: tooth type (central incisor, canine, and first molar), 2D reference points, and aligner type. Data were analyzed and compared using analysis of variance and Tukey's post-hoc tests (p < 0.05). Results: Tooth type, dental region, and aligner type affected both the gap width and aligner thickness. The aligner thickness remained moderately stable across the arch only in the F22. Conclusions: All thermoformed samples displayed smaller aligner thickness and gap width at anterior teeth and both gingival and coronal centers than at posterior teeth and occlusal surfaces.

Keywords

References

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