Note: Chlorhexidine may cause staining of the tooth, tooth filling, and dentures or other mouth appliances. Tetracycline use during tooth development phases (from the last half of pregnancy through eight years of age) may cause permanent discoloration (yellow, gray, brown) of teeth.
What is Coal made of? Coal is made from trees or plants that decayed on the ground for millions of years. The remains of various plants and trees then mixed with the other components of the ground and eventually going through several natural processes making them more like solid rocks.
tar. see tar and pitch tar and pitch,viscous, dark-brown to black substances obtained by the destructive distillation of coal, wood, petroleum, peat, and certain other organic materials.The heating or partial burning of wood to make charcoal yields tar as a byproduct and is an ancient method for the.....he low-temperature (500Â°-600Â°C) dry distillation of coal or peatâthat is, semicokingâyields so-called primary tar. The coking of coal yields coal tar. The tar formed by heat treating wood is called wood tar.