Porcelain crowns (ceramic crowns) and porcelain fused to metal are two of the most common crown types available. Porcelain is extremely durable and provides realistic aesthetics. When combined with an inner metal component, the structural strength is improved, though the tooth may appear darker in color and the metal might be visible above the gum line. With improved techniques and materials, the porcelain fused to metal crowns are a widely used option.