20.500.12556/RUL-135410 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 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. nickel hypersensitivity orthodontic wires surface coating surface roughness preobčutljivost na nikelj ortodontske žice površinski premaz hrapavost površine true false true Angleški jezik Slovenski jezik Članek v reviji 2022-03-11 11:49:37 2022-03-11 11:49:38 2022-09-14 04:13:10 0000-00-00 00:00:00 2022 0 0 11 str. iss. 6, art. 1994 Vol. 15 2022 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 620.1:616.314-089.23 1996-1944 10.3390/ma15061994 100569859 RAZ_Jusufi_Osmani_Zana_2022.pdf RAZ_Jusufi_Osmani_Zana_2022.pdf 1 02D43FC8F8D1828295C8188847C383FF a72e7eb03238ad74cce60520aa1dee44c3417a3e18ad13449a183ae09960f0ec 43cf39ff-a12a-11ec-8556-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=154474 https://www.mdpi.com/1996-1944/15/6/1994 1 f3970285-a128-11ec-8556-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=154472 Zdravstvena fakulteta 0 0 0