Fluoride has become an effective agent for the prevention of dental caries. In an effort to provide adequate fluoride levels to the public, fluoridation of drinking water has become widespread. However, exposure of developing teeth to high levels of fluoride can result in fluorosis, which varies in appearance from white striations to stained pitting of the enamel in both primary and permanent teeth. Current models suggest that the early maturation stage of enamel formation is when the tooth is most susceptible to elevated fluoride levels. Zebrafish exhibit periodic tooth replacement throughout their lives, thereby providing continuous access to teeth at developmental stages particularly susceptible to fluoride exposure. Zebrafish teeth do not contain true enamel, but consist of a hard enameloid surface. Objective: To test the zebrafish (Danio rerio) as model organism for the study of dental fluorosis. Methods: Embryonic and juvenile stage zebrafish were raised in zebrafish water containing NaF at a variety of concentrations. Following treatment, tooth morphology was assessed by bright field and scanning electron microscopy. Programmed cell death in pharyngeal tooth tissues was examined by TUNEL analysis. Results: Zebrafish enameloid developed fluorosis upon exposure to fluoride at concentrations of 38 ppm, as indicated by a severely pitted appearance. Preliminary results also suggest that increased apoptosis may contribute to developing enameloid defects. Conclusion: We conclude that zebrafish may be a useful model organism for the study of dental fluorosis. Supported by NIDCR grants DE14683, DE14084 and DE13237.

Back to the Mineralized Tissue Program
Back to the IADR/AADR/CADR 82nd General Session (March 10-13, 2004)

Top Level Search