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BioMed Research International
Volume 2014 (2014), Article ID 143283, 7 pages
Research Article

Differences of Cytotoxicity of Orthodontic Bands Assessed by Survival Tests in Saccharomyces cerevisiae

1Department of Orthodontics, Dentistry Faculty, Pontifícia Universidade Católica do Rio Grande do Sul, Avenida Ipiranga 6681, Building 6, Room 209, 90619-900 Porto Alegre, RS, Brazil
2Immunology and Microbiology Laboratory, Biosciences Faculty, Pontifícia Universidade Católica do Rio Grande do Sul, Avenida Ipiranga 6681, Building 12, Lab 12D, 90619-900 Porto Alegre, RS, Brazil

Received 19 October 2013; Revised 6 December 2013; Accepted 7 December 2013; Published 6 January 2014

Academic Editor: Susana Viegas

Copyright © 2014 Tatiana Siqueira Gonçalves et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The aim of this study was to evaluate the cytotoxicity induced by orthodontic bands through survival tests on Saccharomyces cerevisiae, a microorganism that presents several genetic and biochemical characteristics similar to human cells. Three groups of bands were evaluated: silver soldered (SSB), laser soldered (LSB), and bands without any solder (WSB). Yeast cells were directly exposed to the bands and indirectly, when a previous elution of the metals in artificial saliva was performed. The negative control was composed of yeast cells or artificial saliva not exposed to any kind of metal. In the direct exposure experiments, all tested groups of bands induced a slight reduction in yeast viability compared to the control. This effect was more intense for the SSB, although not statistically significant. For the indirect exposure experiments, the SSB induced a statistically significant decrease in cell viability compared to the LSB. There were no significant differences between the survival rates of the negative control and the LSB group in both direct and saliva tests. SSBs were cytotoxic, whilst LSBs were not, confirming that laser soldering may be a more biocompatible alternative for use in connecting wires to orthodontic appliances.