Staining within the tooth as opposed to being on the surface (extrinsic). The common causes of intrinsic staining in vital (live) teeth are tetracycline staining, fluoride mottling, and inherited or acquired disorders such as amelogenesis imperfecta. In non-vital (dead) teeth, intrinsic staining is usually the result of pulpal haemorrhage following trauma, a dead pulp (pulpal necrosis), or contamination of the dentine with blood breakdown products following root canal therapy. Treatment is usually by bleaching, microabrasion to remove the discoloured tissue, or by covering the visible tooth surface with a veneer or crown. Compare extrinsic tooth staining.
Sulieman M. An overview of tooth discoloration: extrinsic, intrinsic and internalized stains. Dent Update 2005;32(8):463–4, 466–8, 471.