Patterns of fluoro-gold entry into rat molar enamel, dentin, and pulp.
Permeabilities of enamel and dentin are not fully understood despite their importance for caries, restorative materials, and pulp-dentin-enamel interactions. We have found that Fluoro-Gold is useful for examining tooth permeability, and we designed studies to test the effects of aging, injury, neural function, and dentinal repair on its influx into vital rat teeth. We used fluorescence microscopy and immunocytochemistry to show that Fluoro-Gold rapidly penetrates enamel, the dentin-enamel junction, and outer dentinal acellular tubules, and then concentrates in odontoblasts, where it remains for weeks. As predicted, influx was greatest in immature teeth, and formation of reparative dentin impeded it. We expected that denervation would disrupt influx, because of neural regulation of dentinal fluid movement, but it did not. Damage to odontoblasts under injured dentin caused increased influx and efflux of Fluoro-Gold. Analysis of our data suggests that permeabilities of enamel and dentin to Fluoro-Gold are age-related, inter-dependent, and regulated by odontoblasts.
Byers
M R
MR
Department of Anesthesiology, Box 356540, University of Washignton, Seattle, 98195-6540, USA. Byersm@u.washington.edu
Lin
K J Yoon
KJ
D000375:Aging; D000704:Analysis of Variance; D000818:Animals; D003714:Denervation; D003745:Dental Enamel Permeability; D003782:Dental Pulp / Q000378:metabolism*; D003789:Dental Pulp Exposure / Q000378:metabolism; D003806:Dentin Permeability; D003809:Dentin, Secondary / Q000378:metabolism; D005456:Fluorescent Dyes / Q000493:pharmacokinetics*; D008297:Male; D008340:Mandibular Nerve / Q000502:physiology; D009804:Odontoblasts / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018709:Statistics, Nonparametric; D013266:Stilbamidines; D018677:Tooth Injuries / Q000378:metabolism
C049774:2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt; D005456:Fluorescent Dyes; D013266:Stilbamidines