The main weapons against plaque and plaque formation are the toothbrush, floss and other oral hygiene aids such as toothpicks and rubber tips. The mechanical break-up and removal of the plaque on a daily basis is required to prevent tooth decay and gum disease. The chemicals found in toothpaste and mouthrinses can also aid in this battle but are not a substitute for the mechanical removal of plaque. Once plaque has caused a cavity, no amount of brushing will make it go away, and a filling is needed. Once plaque has caused gum disease, there are several treatment options available to you.
Prevention is always the best way to go.