Tea is normally bad for oral health. It is a low pH drink that increases the acidity of the mouth and cause erosion of the enamel. Sweetened tea is even worse because it contains sugars which bacteria converts into acid and promotes tooth decay. Black teas are an exception.
How does it work?
Black and green teas are made of natural tea leaves and do not contain the artificial sweeteners that other teas normally do. They have polyphenols, compounds that inhibit the growth of bacteria that cause cavities and gum problems. Researchers from the University of Illinois at Chicago discovered that people who used black tea to rinse their mouths for a full minute ten times a day had less buildup of plaque on their teeth compared to participants who used water to rinse their mouths.
A review published in the British Nutrition Foundation’s Nutrition Bulletin found that black tea fights off Streptococcus mutans and Lactobacillus, two different bacteria associated with oral health problems. Scientists also discovered that even with the addition of sugar, black tea continued to prevent tooth decay. Green tea had a similar effect according to the research, going as far as preventing bad breath. Black and green teas have anti-microbial properties since they are high in flavonoids and catechins.
Recommendation: Drink 3 to 4 cups of black or green tea every day to keep your teeth in excellent state.