Table salt contains 97-99% sodium chloride (NaCl). Pure NaCl is white, but may have purple or blue tinge from impurities. Sea salt is dull brown or gray, while rock salt varies in color
Fluoride is a trace mineral found naturally in foods and water. Most fluoride is absorbed in gut and stored in bones and teeth. Recommended daily intake is 4 mg for men, 3 mg for women
Fluoride is a natural mineral found in toothpaste and drinking water. It is the ionized form of neutral fluorine atom. Found in foods like eggs, spinach, meat, fish, tea, oats and rice
Fluoride naturally occurs in soil, water, plants, and foods. Most fluoride comes from fluoridated water and dental products. About 80% of oral fluoride is absorbed in gastrointestinal tract. Fluoride is stored in bones and teeth, excreted in urine
Fluoride is a trace element found mainly in bones and teeth. Daily requirement for dental health is only a few milligrams. Absorbed in stomach and small intestine, enters mineralized tissue
Ancient Egyptians used twigs and leaves for tooth cleaning as early as 3000 BC. Islamic tradition uses miswak five times daily since 610 AD. Modern toothbrushing became common in Europe from late 17th century. First mass-produced toothbrush developed in England by William Addis in 1780