What is the primary cause of tetracycline discoloration in teeth?

Tetracycline discoloration of teeth primarily occurs due to the excessive use of the antibiotic tetracycline during the time when the teeth are still developing, particularly in children. This medication can bind to calcium ions and, as a result, can become incorporated into the tooth structure. When tetracycline is present during the formative years, it can lead to intrinsic staining, resulting in a range of discoloration from yellow to gray or brown in the teeth.

Other factors, such as fluoride exposure and poor oral hygiene, contribute to dental issues and stain formation but do not directly cause the specific type of discoloration associated with tetracycline. Genetic factors may also play a role in individual susceptibility to dental imperfections or discoloration, but they are not the primary cause associated with tetracycline. Thus, the excessive use of tetracycline during the tooth development phase is the key factor leading to this distinctive discoloration.