If you have early cavities that haven’t yet affected the dentine and are still in the enamel outer layers, they may be resealed by applying high fluoride paint, which encourages the tooth to add mineral content. If your diet includes a great deal of sugar or you don’t take very good care of your oral health, a cavity may form close to your tooth surface. This problem can be solved by improving your habits, and decay may stop. This is known as “arrested decay”. However, if your cavity has progressed into the dentine, it needs to be filled.