This patient had a back lower molar that started to hurt when he would bite into foods. He also said that he could feel some discomfort with cold and hot drinks. Dr. Jordan examined the area and did some testing to determine which tooth was causing the pain. As you can see from the first picture, there is a small crack line starting at one end of the tooth and extending towards the cheek side of the tooth. After removing the old silver filling, you can clearly see the crack and which direction it spreads. A dental crown was needed to prevent the crack from spreading. If the crack was allowed to spread, it would likely extend into the nerve of the tooth and then into the roots and the tooth would be lost.