Cytotoxicity and estrogenicity of Invisalign appliances

Eliades, Theodore; Pratsinis, Harris; Athanasiou, Athanasios E.; Eliades, George; Kletsas, Dimitris

doi:10.1016/j.ajodo.2009.03.006

« Previous Next »American Journal of Orthodontics & Dentofacial Orthopedics
Volume 136, Issue 1 , Pages 100-103, July 2009

Cytotoxicity and estrogenicity of Invisalign appliances

Theodore Eliades
- Associate professor, Department of Orthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece
- Reprint requests to: Theodore Eliades, 57 Agnoston Hiroon St, Nea Ionia 14231, Athens, Greece
Harris Pratsinis
- Assistant researcher, Laboratory of Cell Proliferation and Ageing, National Center for Scientific Research “Demokritos,” Athens, Greece
Athanasios E. Athanasiou
- Professor and director, Department of Orthodontics, School of Dentistry, Aristotle University of Thessaloniki, Greece
George Eliades
- Professor and director, Department of Biomaterials, School of Dentistry, University of Athens, Athens, Greece
Dimitris Kletsas
- Director, Laboratory of Cell Proliferation and Ageing, Institute of Biology, National Center for Scientific Research “Demokritos”, Athens, Greece

Received 26 January 2009; received in revised form 23 February 2009; accepted 4 March 2009.

Introduction

Our purpose was to study the in-vitro cytotoxic and estrogenic properties of Invisalign appliances (Align Technology, Santa Clara, Calif).

Methods

Three sets, each consisting of a maxillary and a mandibular appliance, of as-received aligners were immersed in normal saline solution for 2 months. Samples of eluents were diluted to 3 concentrations (5%, 10%, and 20% vol/vol) and tested for cytotoxicity on human gingival fibroblasts and estrogenicity by measuring their effect on the proliferation of the estrogen-responsive MCF-7 breast cancer cells. All assays were repeated 4 times for each maxillary and mandibular set, and the results were analyzed with 2-way analysis of variance (ANOVA) with appliance and concentration serving as predictors at the .05 level of significance; differences among groups were investigated with the Tukey test.

Results

There was no evidence of cytotoxicity on human gingival fibroblasts and no stimulation of proliferation of the MCF-7 cell line at any concentration, indicating no estrogenicity of aligner eluents.