Evaluation of calcium and magnesium contents in tooth enamel without any pathological changes: in vitro preliminary study.

Enamel is the structure that covers the entire clinical crown of a tooth. It enables to chew and crush food, and gives a final shape to the crowns of teeth. To evaluate calcium and magnesium contents in tooth enamel and analyse relationships between the study minerals extracted human permanent teeth were cut at every 150 microns and subjected into acid biopsy. The amounts of calcium and magnesium were assessed in the laboratory using atomic absorption spectroscopy with an air/acetylene flame. The lowest calcium and magnesium contents were found on the enamel surface of the teeth. Statistically significant correlation between the calcium and magnesium concentrations was found at a depth between 150 and 900 µm. Calcium and magnesium contents increased with increasing enamel depth. Calcium and magnesium deposits appeared to be stable through all the enamel layers studied. It would be suggested that mineralization/demineralization affect only external layer of the enamel, whereas deeper layers are not affected by these processes.

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.