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

OBJECTIVES: The 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 METHODS: Fifteen 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. RESULTS: The 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. CONCLUSION: The 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.