MLD is usually caused by the lack of an important enzyme called arylsulfatase A. Because this enzyme is missing, chemicals called sulfatides build up in and damage the nervous system, kidneys, gallbladder, and other organs. In particular, the chemicals damage the protective sheaths that surround nerve cells.
What is a dental crown? The anatomy of a tooth can be divided into two basic parts -- the root and the crown. In a person with healthy gums and bone, the root of the tooth is covered by the gums and bone. The part of the tooth that is visible in the mouth, above the gum line on lower teeth and below the gum line on upper teeth, is called the clinical crown. A cemented restoration that partially or completely covers the outside of the clinical crown is referred to as a dental crown or cap.
According to WedMd.com, a dental crown can be used to: 1  Protect a weak tooth. 2  Restore a broken tooth. 3  Support a tooth with a large filling. 4  Hold a dental bridge in place. 5  Cover misshapen or discolored teeth. 6  Cover an implant. 7  Improve the appearance of a tooth.