Epidemiological surveys have reported that some populations who drink tea on a regular basis have a reduced number of carious teeth. Proposes mechanisms for tea`s oral health benefits include:
1. Fluoride: The tea plant (Camellia Sinensis) extracts fluoride form the soil , which then accumulates in its leaves. For this reason tea is a very rich source of fluoride ; dry tea leaves may contain 4-400 ppm florid eth brewed tea 0.34-6 ppm resulting in one cup of tea containing between 0.3mg and 0.5mg of fluoride. In fact, in the UK the majority of floride comes from tea, providing 70% of our daily intack.
2. Tannins: Other components of tea may also contribute to the inhibition of caries. It has been reported that the tannins in tea can inhibit salivary amylase thereby reducing the cariogenic potential of starch-containg foods. A number of studies have also demonstrated that tannic acid inhibits the growth of S. mutans Bacteria, a major factor in the build-up of dental plque.
3. Acid erosion: In addition to its beneficial effect on plaque, tannin , along with other components of tea such as catechin , caffeine and tocopherol have been shown to be effective in increasing the acid resistance of tooth enamel. Their effects increased dramatically when they were used in combination with fluoride.
4. Flavonoids: Green tea and specific flavonoids, mainly catechins, have exhibited inhibitory effects on the growth cariogenic bacteria by inhibiting the adherence and growth of plaque bacteria the tooth surface.