The role of fluoride on eruption of mandibular molar of albino rats

Eruption of the tooth is a complex and highly regulated process which can be influenced by genetic, environmental and systemic factors. Fluoride is found naturally in water as well as in foods and dental products. The first mandibular molar is the first molar to erupt and it is essential for  mastication of food. We studied the effect of fluoride on the eruption of the first mandibular molar in albino rats. Fluoride at different  concentrations was added to the water of pregnant albino rats while sterile water without fluoride was given to the control pregnant dams. The pregnant dams were allowed to deliver, and the heads of their pups carefully decapitated, and mandibles dissected out on days 10, 12, 15 and 18 for assessment of eruption pattern of the first molar while also measuring the mandibular length and breadth. The mandibles were then processed for hematoxylin and eosin staining. On gross examination, some of the teeth developed intraosseously while others were located mucosally, pre-occlusally or occlusally. There was significant reduction in both the birth weight and mandibular length as the fluoride concentration increased compared to the control but a significant increment in the mandibular breadth between the experimental groups in comparison with the control group on day 15 (p value <0.05). These findings suggest that high concentrations of fluoride could delay mandibular molars’ eruption and also cause low birth weight. Key Words: fluoride, mandibular molar, tooth eruption