The evaluation of zinc and copper content in tooth enamel without any pathological changes – an in vitro study

Abstract

ObjectivesThe objectives of the study were to evaluate the content of copper and zinc in individual layers of tooth enamel and to analyze the relationships between the study minerals in individual layers of tooth enamel.Patients and methodsFifteen human permanent teeth were cut off every 150 μm alongside the labial surface. Acid biopsy of each layer was performed. The zinc content was determined using the air–acetylene flame method. The copper content was determined using the electrothermal technique with argon.ResultsThe mean zinc concentrations increased significantly starting from the outer enamel surface, with the maximum concentration in the 150–300 μm layer. The mean copper concentrations increased substantially from the outer enamel surface to a depth of 150 μm, and then a slight downward trend of this mineral levels was seen, down to a depth of 450 μm. Strong positive correlation was found between the zinc and copper concentrations at depths of 150–300, 450–600 and 600–750 μm.ConclusionThe levels of zinc and copper in the outer enamel layers may have an effect on the increased content of unipolar minerals at deeper enamel layers. The content of the study elements determined may reflect the process of mineralization and maturation of enamel in the pre-eruption period.

Synchrotron X-ray fluorescence mapping of Ca, Sr and Zn at the neonatal line in human deciduous teeth reflects changing perinatal physiology

“…Zinc exchange from the posteruptive oral environment may well contribute to this surface enrichment (Humphrey et al 2008a) but it is notable in this study that worn enamel, despite having being exposed to saliva, is not Zn rich. Zinc at the enamel surface has also been tentatively linked to the intense involvement of Zn in the process of enamel mineralisation and maturation (Humphrey et al 2008a;Klimuszko et al, 2018;Müller et al, 2019).…”

“…Zinc reaches highest levels in the ameloblast nucleus during enamel maturation and Zn a component of alkaline phosphatase, of carbonic anhydrase, of MMP-20 and KLK4 (Klimuszko et al, 2018). Zinc is also a potent inhibitor of serine proteases including KLK4 and so may act to modulate enamel protein degradation.…”

“…Robinson et al (1997), however, have observed that during the final maturation phase there is relatively free access of diffusible ions (such as Mg) into the enamel and it may well be that relatively free diffusion of Zn ions during maturation contributes to the Zn-rich surface enamel layer. Surface exchange from Zn present in the diet and the oral environment will also surely accumulate at the enamel surface of teeth examined many years post-eruption such as those included in this study (Klimuszko et al, 2018;Müller et al, 2019;Humphrey et al, 2008a).…”

The Effect of Peat Swamp Water on Tooth Demineralization of Copper and Selenium Ion

“…12,13 Other factor that may affect copper ions is that the copper ions contained in teeth created a protective layer in the form of copper (II) phosphate (Cu 3 (PO 4 ) 2 ) on the enamel surface, thus making the enamel more resistant to environmental changes, especially acidic environment. 9 The results of this study showed that copper ion release on peat water group was less than immersion in artificial saliva and tap water. This may be caused by adsorption reaction between hydroxyapatites and free copper ions in the solution.…”

“…Copper ions are also able to become cariostatic agents by inhibiting the development and metabolism of bacteria. 9 Aside from copper ions, other minerals that can be released when the teeth are exposed to acids are selenium ions (Se 4+ ). The presence of selenium ions in tooth can increase the susceptibility of teeth to caries.…”