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. 2024 Nov 1;94(6):664-671.
doi: 10.2319/112823-788.1.

The corrosion products of proprietary and generic orthodontic fixed lingual retainers and their in-vitro cytotoxicity

Nessa A Finlay, Lam Cheng, Elizabeth Kelly, Peter Petocz, Narayan Gandedkar, Mehmet Ali Darendeliler, Oyku Dalci

The corrosion products of proprietary and generic orthodontic fixed lingual retainers and their in-vitro cytotoxicity

Nessa A Finlay et al. Angle Orthod. .

Abstract

Objective: To assess the corrosion products and cytotoxicity of generic and proprietary fixed lingual retainers (FLRs).

Materials and methods: Seven FLRs were investigated. Wires were submersed in solution for 34 days, at 37°C, under constant agitation. A proportion of this solution was analyzed to determine the concentration of metallic ions leaching off the wires. The remainder was diluted to 5%, 10% and 20% followed by exposure to human gingival fibroblasts and analysis of cytotoxicity of the wires.

Results: Three wires (Dentaflex, Universal, and AZDent) released excessive concentrations of lead, two wires (MeshMark and Orthoflex) released excessive concentrations of nickel, and one wire (Universal) released excessive concentrations of molybdenum into solution. No statistically significant difference was found between the wires analyzed (P = .24). Slight cytotoxicity was noted in only one wire (Dentaflex) at a 20% dilution of eluent. This was also the wire which released the highest concentration of lead into solution. All other wires, at all concentrations, were deemed noncytotoxic, but five samples overall were deemed statistically significant (P < .0024). A statistically significant difference existed between wires (P = .013) and concentrations analyzed (P < .001).

Conclusions: Metals were released in differing quantities from all wires, with some elemental concentrations measuring more than that deemed acceptable in drinking water in Australia. A trend toward increased cell viability across samples was found with only one demonstrating cytotoxicity. There was no indication that generic FLRs were more or less biocompatible than their proprietary counterparts.

Keywords: Corrosion; Cytotoxicity; Fixed lingual retainer; Orthodontics; Retainers.

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Figures

Figure 1.
Figure 1.
96-well plate design.
Figure 2.
Figure 2.
Mean cell viability relative to positive control.
See this image and copyright information in PMC

References

    1. Little RM. Stability and relapse of mandibular anterior alignment: University of Washington studies. Semin Orthod. 1999;5(3):191–204. doi:10.1016/S1073-8746(99)80010-3 - DOI - PubMed
    1. Meade MJ, Dreyer CW. A survey of retention and retainer practices of orthodontists in Australia. Australas Orthod J. 2019;35(2):174–183. doi:10.21307/aoj-2020-047 - DOI
    1. Haleem, Riyam, Shafiai NAA. Perspective on metal leachables from orthodontic appliances: a scoping review. J Int Oral Health. 2021;13(6):539–548. doi:10.4103/JIOH.JIOH_52_21 - DOI
    1. Sifakakis I, Eliades T. Adverse reactions to orthodontic materials. Aust Dent J. 2017;62:20–28. doi:10.1111/adj.12473 - DOI - PubMed
    1. Kerosuo H, Moe G, Kleven E. In vitro release of nickel and chromium from different types of simulated orthodontic appliances. Angle Orthod. 1995;65(2):111–116. doi:10.1043/0003-3219(1995)065<0111:IVRONA>2.0.CO;2 - DOI - PubMed

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