You may require a dental filling as a result of the corrosive action of tooth decay. As time progresses, cavities begin to form, which are tiny pits or holes in the enamel of your teeth. These cavities can begin to affect the shape of your teeth and can cause pain and sensitivity. If left untreated, destruction and infection of the inner parts of the teeth, such as the pulp (which contains the tooth’s nerve endings) can occur. Dental fillings thus have a restorative function and serves as a preventative measure (prevents the need for root canals and extractions).