TETRACYCLINES AND PERMANENT TEETH: THE RELATION BETWEEN DOSE AND TOOTH COLOR

Abstract

A quantitative estimation of the darkening effect of tetracyclines on permanent incisors was made by correlating tooth colors with the recorded history of tetracycline exposure in 160 children under our care since infancy. The average darkening caused by one 6-day course of oral tetracycline or demethylchlortetracycline during the years of permanent incisor formation was 0.3 of a shade on a 14 shade dental scale. Children with five such courses of tetracycline therapy during the first 4½ to 5 years of life had permanent incisors averaging about two shades darker than children with no tetracycline exposure, a nearly imperceptible and cosmetically negligible difference; however, 3 of these 14 children had moderately darkened teeth. With greater frequency of tetracycline exposure, the risk increases; four of our six patients with eight or more courses had noticeably dark teeth. After age 6 for girls and 7 for boys the risk of tetracycline staining can be ignored since the cosmetically important anterior teeth have all formed. When tetracycline therapy is indicated during the first 6 to 7 years, the use of oxytetracycline (or possibly doxycycline) may diminish tooth darkening.