Postnatal effects of nicotine on first molar development in the CD-1 mouse

Young CD-1 mice, 4 days old, exposed to 0.1% nicotine sulfate on gestational days 6-20 were compared with untreated pups of the same age to determine its effect on the development of mandibular first molars. Pregnant mice were given intraperitoneal injections of nicotine at a dose of 1.67 mg/kg/day. Pups were then decapitated, their entire mandibles were excised, routinely prepared and embedded in paraffin, sectioned in the frontal plane and stained with hematoxylin and eosin for histological examination of developing lower first molars. The results demonstrated that the process of odontogenesis appears retarded in nicotine-treated animals while the molars of the control group revealed dentin and enamel formation. It was concluded that nicotine has a detrimental effect on molar development. Nicotine may interfere with cellular maturation of the tooth germ indicating that this effect is prenatal and extends postnatally.