Chewing of gum is a common habit, with about 100,000 tons chewed worldwide every year, the World Dental website reports. Chewing gum after eating helps stimulate saliva production, which neutralizes and wash away acid produced by the bacteria in plaque --- acid that causes bad breath and tooth decay. Chewing gum can also help relieve sinus and ear pressure.
General Effects
Chewing gum contains some type of sweetener, usually sugar, sorbitol, or xylitol. Chewing gum containing sugar can be harmful to your teeth, especially if chewed often, or removed too quickly from the mouth.
According to World Dental, some studies have shown that if you chew a gum with sugar, you should chew it for at least 15 minutes. After 15 minutes, the sugar in the gum is gone, and the beneficial effects of increased saliva production can wash away the sugar remaining on your teeth.
Tooth Decay
The combination of saliva, bacteria, and sugar may lead to tooth decay. After chewing gum containing sugar, an Elmhurst College report notes, sticky glycoproteins --- a combination of protein and carbohydrate --- adhere to the teeth, which starts plaque formation. At the same time, millions of bacteria, including streptococcus mutans, are also sticking to the glycoprotein. Although there are many different bacteria in your mouth, streptococcus mutans is the kind that causes cavities.
Tooth decay occurs when the acid-producing bacteria in plaque dissolve the essential minerals in your tooth enamel. Teeth are most vulnerable immediately after eating or drinking, when plaque acid levels are at their highest.
Fuel for Bacteria
Not only does sugar play a harmful role in tooth decay when it combines with saliva and bacteria, but, according to HealthyTeeth.org, the bacteria that form plaque actually uses the sugar as a source of energy. In combination with sugar, the bacteria multiply more quickly, which causes the plaque to grow in size and thickness. The bacteria also turn the sugar into a glue-like substance, which they use to help themselves stick to tooth surfaces --- which in turn makes it harder for your saliva to wash them away.
