A histological study of the short-term effects of fluoride on enamel and dentine formation in hamster tooth-germs in organ culture in vitro.
First maxillary molars in early stages of secretory amelogenesis were exposed in vitro to fluoride (F-) concentrations ranging between 2.63 microM and 2.63 mM for up to 3 days. In contrast to the dentine papilla, which seemed unaffected by F- in concentrations up to 1.31 mM, the enamel organ was dose-dependently extremely sensitive for F-. Young ameloblasts which became secretory in vitro were in particular sensitive and did not secrete enamel adjacent to new, in vitro-formed dentine. Hypermineralization of the dentine at the enamel-dentine junction suggested that these ameloblasts still transport and deposit minerals. 52 microM was the lowest concentration of F- that inhibited deposition of enamel in the cervical-loop region. Ameloblasts, secretory at the time of exposure to F-, in concentrations of 52 microM up to 1.31 mM secreted an abnormal, amorphous, von-Kossa-negative enamel matrix. 1.31 mM of F- was the lowest concentration which induced the formation of a hypermineralized band in the pre-exposure enamel. 2.63 mM of F- was highly toxic for the enamel organ but had only moderate effects on the dentine papilla.
D000566:Amelogenesis / Q000187:drug effects*; D000818:Animals; D006224:Cricetinae; D003771:Dental Papilla / Q000187:drug effects; D003810:Dentinogenesis / Q000187:drug effects*; D004658:Enamel Organ / Q000187:drug effects; D008647:Mesocricetus; D008963:Molar / Q000473:pathology; D009924:Organ Culture Techniques; D012969:Sodium Fluoride / Q000494:pharmacology*; D014083:Tooth Germ / Q000187:drug effects* / Q000473:pathology
D012969:Sodium Fluoride