Virulence modulation of Streptococcus mutans biofilms by metal ions released from orthodontic appliances

Abstract

Objectives: To evaluate the impact of metal ions commonly shed from orthodontic appliances on the virulence of Streptococcus mutans ATCC®25175TM biofilms. Materials and Methods: Biofilms were grown in the presence of Ni 2+, Fe3+, Cr3+, Co2+, and a metal ion pool at concentrations similar to those released in saliva of orthodontic patients for 72 hours. Once mature, biofilms were treated for up to 12 hours with 5% glucose. Results: Ions interfered with the growth of S mutans by reducing its biomass (Ni2+, Fe3+, Cr3+), raising its rates of sugar metabolism (Ni2+, Fe3+, Cr 3+), and raising its secretion of lactate (Ni2+, Fe 3+, Cr3+, pool). Conclusion: The laboratory data presented here point to the possibility of virulence increase of Smutans by metal ions commonly released during orthodontic therapy. (Angle Orthod. 2013;83:987-993.). © 2013 by The EH Angle Education and Research Foundation, Inc.