enamels

Enamels refer to two related but distinct materials. In dentistry, dental enamel is the hard outer layer of teeth, protecting the underlying dentin from wear and decay. In metalwork, ceramics and glass, vitreous enamel (often called porcelain enamel) is a glassy coating fused to a substrate to provide decoration, color and chemical resistance.

Vitreous enamel is produced by applying a finely ground glass frit to a prepared surface and firing it at high temperatures (typically around 750–900°C / 1400–1650°F) until the particles melt and fuse into a continuous, non-porous coating. The glaze typically contains silica as a base with fluxes and stabilizers, and colorants such as metal oxides to achieve the desired hues. It adheres best to metals and certain ceramics when thermal expansion is matched to the substrate. Techniques include painting or applying powder by sifting, as well as decorative methods such as cloisonné and champlevé.

Dental enamel is comprised mainly of hydroxyapatite crystals and is the hardest tissue in the human body. It forms during tooth development and does not regenerate. Its high mineral content gives wear resistance and a protective barrier against decay, but it is susceptible to acid erosion and physical abrasion.

Industrial and artistic enamels are used on cookware, architectural surfaces, jewelry and art objects. They are valued for their durability, color range and chemical resistance but can chip or craze if subjected to abrupt temperature changes or mechanical impact. Proper care involves avoiding thermal shock, using nonabrasive cleansers, and following manufacturer guidance.