Ion release and surface changes of nickel–titanium archwires induced by changes in the pH value of the saliva—significance for human health risk assessment

Jusufi Osmani, Zana (author), Poljšak, Borut (author), Zelenika, Saša (author), Kamenar, Ervin (author), Marković, Kristina (author), Perčić, Marko (author), Katić, Višnja (author)

The aim of this study was to explore whether changes in the salivary pH influence mechanical properties, surface roughness, and ion release from NiTi archwires with various surface coatings, and discuss the clinical significance of the findings. The uncoated, rhodium-coated, and nitrified NiTi wires were immersed into artificial saliva of different pH values (4.8, 5.1, 5.5, and 6.6). Released nickel and titanium ions were measured with inductively coupled plasma-optical emission spectroscopy at the end of 28 days. Atomic force microscopy was used to measure the arithmetic average surface roughness R$_a$, the root-mean-square roughness R$_q$, and the maximum height of the asperities R$_Z$. The nanoindentation hardness (H$_{IT}$) and Young’s modulus (E$_{IT}$) measurements were performed. The change in the pH of artificial saliva is inversely proportional to the release of titanium from both coated and uncoated wires, and the release of nickel from uncoated wires. The surface roughness parameters of both coated and uncoated wires are unaffected by the change in the pH of artificial saliva. The change in the pH of saliva has minor influence on the hardness and Young’s modulus of elasticity of both coated and uncoated wires. The concentration of released metal ions measured was below the recommended upper limit for daily intake; nevertheless, hypersensitivity effects cannot be excluded, even at lower concentrations and at low pH.

• Language: English
• Keywords: nickel hypersensitivity, orthodontic wires, surface coating, surface roughness
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: ZF - Faculty of Health Sciences
• Publication status: Published
• Publication version: Version of Record
• Year: 2022
• Number of pages: 11 str.
• Numbering: Vol. 15, iss. 6, art. 1994
• PID: 20.500.12556/RUL-135410
• UDC: 620.1:616.314-089.23
• ISSN on article: 1996-1944
• DOI: 10.3390/ma15061994
• COBISS.SI-ID: 100569859
• Publication date in RUL: 11.03.2022

Record is a part of a journal

• Title: Materials
• Shortened title: Materials
• Publisher: MDPI
• ISSN: 1996-1944
• COBISS.SI-ID: 33588485

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 08.03.2022

Secondary language

• Language: Slovenian
• Keywords: preobčutljivost na nikelj, ortodontske žice, površinski premaz, hrapavost površine

Projects

• Funder: Other - Other funder or multiple funders
• Funding programme: University of Rijeka
• Project number: uniri-biomed-18-71