kiille

Kiille is a Finnish term used to describe a hard, glassy coating in two main contexts: dental enamel and ceramic glaze. In dentistry, kiille refers to the enamel, the outer mineralized layer of a tooth that protects underlying dentin. Enamel is primarily composed of hydroxyapatite and is acellular, meaning it does not regenerate once damaged. Its thickness varies by tooth and region, commonly ranging from about 0.5 to 2 millimeters. Kiille serves as a protective barrier against wear and acids, and enamel erosion or caries results from mineral loss. Fluoride treatments can strengthen kiille and promote remineralization of early lesions, while extensive damage may require restorative procedures.

In ceramics and glassmaking, kiille denotes the glaze applied to a ceramic body. A glaze is a vitreous coating formed from silica-rich materials mixed with fluxes and colorants. When fired at high temperatures, the glaze fuses to the surface, creating a smooth, glassy, often waterproof layer that enhances color, texture, and durability. Glazes vary in composition and firing requirements, producing gloss, satin, or matte finishes. Proper glaze application and firing are crucial to avoid defects such as crazing or peeling.

The term kiille thus covers both a natural biological material in teeth and a manufactured coating on ceramics. The meaning is determined by context, with dental kiille focusing on tooth health and ceramic kiille on surface aesthetics and protection.