Sugarless gum is proven to help prevent tooth decay. Chewing sugarless gum for 20 minutes, especially after eating, washes away food and other particles left in the mouth. It helps increase saliva flow, which carries calcium and phosphate. Chewing sugarless gum also neutralizes acids produced by bacteria in the mouth. Gum that contains sugar also helps generate the flow of saliva however the sugar also builds plaque on the teeth. Using mouthwash also helps keep the mouth clean, rinsing away debris and killing bacteria.
This is a great alternative to brushing after every meal, but it cannot replace regular brushing and flossing. Chewing gum should not replace regular brushing. You should still brush your teeth at least once a day.
Its best to chew sugarless gum that has the ADA seal. This way you can be sure the brand has met the ADA standards. Companies must verify ingredients with the ADA prior to receiving their seal of approval. This should help assure you that you are getting a quality product.
Read more about the benefits of chewing sugarless gum here http://www.mouthhealthy.org/en/az-topics/c/chewing-gum.aspx