Skip to main content
Article
Structural Conformation and Leaching from in vitro Aged and Retrieved Invisalign Appliances
American Journal of Orthodontics and Dentofacial Orthopedics
  • Susan Schuster, Marquette University
  • George Eliades, University of Athens
  • Spiros Zinelis, University of Athens
  • Theodore Eliades, Aristotle University of Thessaloniki
  • T. Gerard Bradley, Marquette University
Document Type
Article
Language
eng
Format of Original
4 p.
Publication Date
12-1-2004
Publisher
Elsevier
Disciplines
Abstract
The objectives of this study were to investigate the structure of Invisalign appliances (Align Technology, Santa Clara, Calif) after intraoral exposure, and to qualitatively and quantitatively characterize the substances leached from the aligners after accelerated in vitro aging. Samples of Invisalign appliances were randomly selected from 10 patients before intraoral placement and after retrieval, and the prepared specimens were subjected to (1) bright-field optical reflection microscopy to study the surface morphology; (2) Fourier transform infrared microspectroscopy to characterize the in vivo changes in molecular composition induced on appliance surfaces, (3) scanning electron microscopy and energy dispersive X-ray microanalysis to identify the elemental composition of integuments formed on the surface, and (4) Vickers hardness (HV200) testing. Another set of reference and retrieved appliances was subjected to artificial aging for 2 weeks, and the extracts were subjected to gas chromatography-mass spectroscopy. The retrieved appliances demonstrated substantial morphological variation relative to the as-received specimens involving abrasion at the cusp tips, adsorption of integuments, and localized calcification of the precipitated biofilm at stagnation sites. Buccal segments of retrieved appliances showed an increase in hardness, which might be attributed to mastication-induced cold work; however, the clinical implication of this effect on mechanotherapy is unknown. In vitro aged and retrieved appliances were found to leach no traceable amount of substances in an ethanol aging solution.
Comments

American Journal of Orthodontics and Dentofacial Orthopedics, Vol. 126, No. 6 (December 2004): 725-728. DOI.

Citation Information
Susan Schuster, George Eliades, Spiros Zinelis, Theodore Eliades, et al.. "Structural Conformation and Leaching from in vitro Aged and Retrieved Invisalign Appliances" American Journal of Orthodontics and Dentofacial Orthopedics (2004) ISSN: 0889-5406
Available at: http://works.bepress.com/t_bradley/1/