Titanium alloy miniscrews for orthodontic anchorage: an in vivo study of metal ion release

  • Micéli Guimarães Blaya
  • Diego Segatto Blaya
  • Paola Mello
  • Érico M.M. Flores
  • Luciana Mayumi Hirakata
Keywords: Metal ions, miniscrews, ICP-MS, ICP-OES, orthodontic appliances


Purpose: To examine and compare the levels of several metal ions released in the saliva of patients with orthodontic appliances, at different time points before and after insertion of a miniscrew. Methods: Saliva of patients (n=20) was collected at four time points: before miniscrew placement (T1), 10 minutes (T2), 7 days (T3) and 30 days after miniscrew placement (T4). The salivary samples were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES). The release of nine different metal ions was observed: titanium (Ti), zinc (Zn), chromium (Cr), nickel (Ni), iron (Fe), copper (Cu), aluminum (Al), Vanadium (V) and cobalt (Co). Data were analyzed by descriptive statistics. Salivary metal concentrations from different time points of miniscrew treatment were compared using Wilcoxon paired tests (α=5%). Results: At time point T4, there was a quantitative increase in the salivary concentration of Cu, Ti, V, Zn, as well as a quantitative decrease in the salivary concentration of Al, Co, Cr, Fe, Ni, when compared with T1. Conclusion: It can be concluded that the placement of fixed orthodontic appliances associated with miniscrews does not lead to an increase of salivary metal ion concentrations.

Author Biographies

Micéli Guimarães Blaya
Department of Dental Materials
Diego Segatto Blaya
Department of Oral Surgery
Paola Mello
Department of Chemistry
Luciana Mayumi Hirakata
Department of Dental Materials
Original Article