Background: The use of doxycycline has been avoided before 8 years of age due to known dental staining caused by tetracyclines, although doxycycline differs from classical tetracyclines in many ways. Doxycycline is still an important antimicrobial agent, but its dental safety is not well studied.

Objectives: To examine the state of permanent teeth after doxycycline exposure in children <8 years of age.

Methods: Details of doxycycline treatment were collected from medical records. After the eruption of permanent teeth the dental status was examined by an experienced paediatric dentist for detection of dental staining and enamel hypoplasia. The resulting dental photographs were evaluated by a second independent experienced paediatric dentist.

Results: The mean age of 38 study subjects at the time of doxycycline treatment was 4.7 years (range 0.6–7.9 years, SD 2.3). The doxycycline dose was 10 mg/kg/day (varying from 8 to 10 mg/kg/day) for the first 2–3 days and 5 mg/kg/day (varying from 2.5 to 10 mg/kg/day) thereafter. The mean length of the treatment was 12.5 days (SD 6.0) and ranged from 2 to 28 days. Tetracycline-like staining or enamel hypoplasia of developing teeth was detected in none of the subjects.

Conclusions: Doxycycline treatment of small children does not seem to induce permanent tooth staining.