Mercury fillings, also known as silver fillings, over time create microfractures in teeth. This can cause your teeth to fracture, and if it happens below the gumline, you may not be able to save the tooth. The best way to address the matter is to have them removed. There are safe ways for the removal of mercury fillings, so this should be discussed with your dentist before it is done. NOT ALL dentists do mercury removal in a safe manner. Some fillings can be replaced with small composite, or white, fillings. Others may need to be replaced as inlays, onlays, or crowns. This depends on the size of the existing filling as well as the condition of the tooth.