Dental fillings are used to replace missing tooth structure that has occurred as a result of disease or damage. The decay of a tooth causes it to become hollow. Dental fillings help to close this gap and keep it from decaying further. Fillings are also used to restore fractured or cracked teeth, as well as teeth that have worn away due to dental habits such as teeth grinding and nail biting. If you have decay, it is critical to get Fillings done as soon as possible because if the treatment is not completed promptly, the enamel (outer layer of the teeth) will begin to decay, exposing the dentin (the hard part below the enamel). When bacteria in your mouth come into touch with dentin, infection results. You will experience sensitivity once the infection has begun, and you will desire to get Fillings done.