Influence of Cu Addition and Autoclave Sterilization on Corrosion Resistance and Biocompatibility of NiTi for orthodontics Applications

Camila Dias Dos Reis Barros,José Antônio Da Cunha Ponciano Gomes

doi:10.1590/1980-5373-mr-2020-0369

Camila Dias Dos Reis Barros, José Antônio Da Cunha Ponciano Gomes

Open Access

https://doi.org/10.1590/1980-5373-mr-2020-0369

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Journal: Materials Research	Publication Date: Jan 1, 2021
Citations: 1	License type: CC BY 4.0

Affiliation: Universidade Federal do Rio de Janeiro

Abstract

Commercial archwires NiTiCu (Ormco) and NiTi (Morelli) and samples of the corresponding raw materials were tested to assess the influence of Cu addition and sterilization on the corrosion resistance and biocompatibility. Raw materials samples and commercial archwires exhibited similar corrosion resistance when compared. The addition of Cu decreased the corrosion resistance of NiTi alloy, whiling the sterilization process had no influence. The biocompatibility tests were carried out in different extracts of the alloys and no cytotoxicity effects were observed for the ionic concentrations used. SEM and Confocal laser analysis permitted to observe the localized corrosion morphology obtained after anodic polarization tests. Although Cu addition on NiTi can be introduced to better adjust the mechanical resistance, this third element induced detrimental effect on the corrosion resistance of raw materials and commercial archwires.

Highlights

NiTi alloys are widely used in orthodontic applications, due to shape memory and superelasticity characteristics[1,2,3,4,5,6]
The relevant result obtained from the anodic polarization test was the localized corrosion susceptibility exhibited by NiTiCu alloy not observed for NiTi alloy
The results clearly indicated the negative impact of the Cu addition on the corrosion resistance of the NiTi alloy, based on the results expressed by the anodic polarization tests

Summary

Introduction

NiTi alloys are widely used in orthodontic applications, due to shape memory and superelasticity characteristics[1,2,3,4,5,6]. The main advantage of using NiTi archwires in orthodontics is the release of continuous and controlled forces responsible to produce the desired teeth movement under elastic deformation[8,9,10]. NiTiCu in orthodontic therapy[1,2,3,4,5,6,7,8,9,10,11,12,13] can exert lower forces being a good selection for the treatment of patients with periodontal disease[4,8,12,15] Another advantage is the antibacterial property of copper benefiting the microflora control[16]

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Discussion

Conclusion