Tooth discoloration resulting from long-term tetracycline therapy: a case report.

Administration of tetracycline to children or pregnant women is known to adversely affect the color of developing teeth. This case report suggests the possibility that discoloration from tetracycline may not be limited to tooth development in the child, but may also affect the adult dentition. When given over long periods of time in adults, the tetracycline molecule is incorporated into the continuously forming secondary dentin. It is possible that chronic sun exposure of the incorporated tetracycline may cause the formation of a reddish-purple oxidation product, resulting in discoloration of the permanent teeth.