Penicillin Disrupts Dental Mineralization in Rats: A Comparative Study With Tetracycline Highlighting Prenatal and Postnatal Risks

Abstract

Objectives: Penicillin's impact on enamel defects remains understudied, particularly regarding its ability to cause structural issues even at therapeutic doses. Material and Methods: Pregnant Wistar rats received daily gavage from gestational day 13–22 with saline (control), 130 mg/kg tetracycline, 50 mg/kg penicillin, or 100 mg/kg penicillin. After birth, pups received the same treatment for 12 days. Upper first molars were analyzed for enamel/dentin thickness, maturation, and histopathological changes. Results: Tetracycline significantly reduced enamel and dentin thickness, disrupted their development, and caused flattening of the dentin-enamel junction (DEJ) compared to the control group. Penicillin at 100 mg/kg also significantly decreased enamel and dentin thickness, impaired their maturation, and led to DEJ flattening. At 50 mg/kg, penicillin did not significantly affect enamel and dentin thickness but still disrupted their development and caused DEJ flattening. Conclusions: Penicillin at 100 mg/kg adversely affected enamel and dentin development, causing significant defects similar to those caused by tetracycline, although the severity and mechanisms may differ. Even at 50 mg/kg, penicillin disrupted enamel and dentin development, underscoring the clinical relevance of these findings and the need for caution when prescribing penicillin during pregnancy, even at lower doses, due to its potential to disrupt dental development.