Teeth may be darkened by a buildup of surface stains (extrinsic staining), which hides the natural tooth color; or the tooth itself may discolor (intrinsic staining).
Teeth maybe be discolored and darkened by two kinds of stains and discoloration, we call it Extrinsic, where the teeth stain is just on the surface, or Intrinsic, which means the tooth itself is discolored.
Extrinsic staining causes:
- Plaque: Virtually invisible on the tooth surface. Plaque may become stained by chromogenic bacteria such as Actinomyces species.
- Calcification: Uncleaned or untreated plaque will calcify, leading to the formation of hard teeth deposits especially around the gums. These deposits of calcium then can become colored from grey to yellow to black.
- Tobacco: The smoke of tobacco and even vapes contain chemicals which form a yellow-brown stain around the teeth and above the gumline.
- Betel chewing.
- Drinking heavily colored liquids whether natural or artificial, sports drinks, cola, coffee, tea, and red wine etc., can all cause teeth discoloration.
- Metallic elements: Exposing teeth to metallic compounds may cause them to discolor/ Metallic compounds sucha as in the form of medicine or external enviroments like Iiron (black stain), iodine (black), copper (green), nickel (green), cadmium (yellow-brown).
Intrinsic staining includes:
- Cavities: tooth decay.
- Dental Trauma: as a result of pulp necrosis or internal resorption..
- Enamel hypoplasia.
- Dentinogenesis imperfecta.
- Antibiotics like Tetracycline and minocycline: Tetracycline is a broad spectrum antibiotic, and its derivative minocycline is common in the treatment of acne. The drug is able to chelate calcium ions and is incorporated into teeth, cartilage and bone. Ingestion during the years of tooth development causes yellow-green discoloration of dentin visible through the enamel which is fluorescent under ultraviolet light. Later, the tetracycline is oxidized and the staining becomes more brown and no longer fluoresces under UV light.
- Hemolytic disease.
Cause of extrinsic and intrinsic staining include:
- Age eventually takes over, the enamel protecting the teeth becomes thinner over time.
- Clenching and grinding of the teeth: Avoid this as much possible, grinding and clenching teeth can lead to micro-cracking of the incisional edges of the teeth. These cracks make extrinsic stain factors easier to latch onto and only a thin layer of enamel is left. This thin enamel layer is half transparent allowing the dark background of the mouth to shine through, making it look darker than it should.