Under the microscope: Hydroxyapatite remineralises tooth enamel
introduction
Human teeth are exposed to constant stress in everyday life. Be it acids from food, acids that are produced by microorganisms or mechanical attacks (e.g. brushing your teeth and chewing). The result is a breakdown of tooth enamel or demineralization. The aim of all cosmetic dental care products (toothpastes and mouthwash solutions) is to counter these attacks as effectively as possible. Fluorides are often used to remineralize tooth enamel more quickly. Hydroxyapatite is increasingly used in dental care. Hydroxyapatite is the main component of tooth enamel. Therefore, it makes sense to use this active ingredient in dental care.
Question
What is the effect of hydroxyapatite on tooth enamel?
material and methods
Extracted premolars were prepared to obtain sterile enamel samples. The samples were divided into three groups which were treated with different toothpastes: fluoride toothpaste, hydroxyapatite toothpaste and a control (water). The enamel samples were brushed three times a day for 30 seconds each time with a toothbrushing machine and the appropriate toothpaste. After cleaning, the samples were rinsed with tap water. The observation period was 15 days. After the series of experiments, all tooth enamel samples were examined microscopically (scanning electron microscopy, transmission electron microscopy, IR spectroscopy) and X-ray.
Results
Hydroxyapatite forms a protective layer on the surface of the tooth enamel, which also withstands external influences (e.g. acids). This protective layer fills in tooth enamel defects and thus supports the remineralization of the same. In contrast to fluoride toothpastes, a clear deposit of hydroxyapatite can be seen. The binding of hydroxyapatite to the enamel surface is of chemical, physical and morphological structure.
conclusion
Hydroxyapatite is able to bind to tooth enamel and repair tooth enamel defects as well as remineralize these defects. In addition, a protective layer is formed that can protect the tooth enamel from further erosive influences.
