title: Effect of iron on inhibition of acid demineralisation of bovine dental enamel in vitro.
abstract: OBJECTIVE
  Iron ions (Fe(2+)) have been shown to be cariostatic in many studies particularly by their ability to reduce bacterial metabolism. Nevertheless, the role of iron ions on dissolution of enamel is unexplored. The aim of the present study was therefore to investigate the protective effect of increasing concentrations (0-120mmol/L) of Fe(2+) on the dissolution of enamel.
  
  
  METHODS
  Enamel powder was subjected to acetic acid made with increasing concentrations with respect to FeSO(4)x7H(2)O. In order to determine the amount of enamel dissolved, the phosphate released in the medium was analysed spectrophotometrically using the Fiske-Subarrow method. Data were tested using Kruskall-Wall and Dunn's tests (p<0.05). The degree of protection was found to approach maximum at about 15mmol/L Fe(2+). Higher concentrations of Fe(2+) did not have an extra effect on inhibition of dissolution of enamel powder. In the next step, the protective effect of 15mmol/L Fe(2+) against mineral dissolution of the bovine enamel was evaluated using a simple abiotic model system. Enamel blocks were exposed to a sequence of seven plastic vials, each containing 1mL of 10mmol/L acetic acid. The acid in vial 4 was made 15mmol/L with respect to FeSO(4)x7H(2)O. The mineral dissolved during each challenge was thus determined by phosphate released as described above. Data were tested using two-way ANOVA (p<0.05).
  
  
  RESULTS
  Lower demineralisation (around 45%) was found in vial 4 (with Fe) that continued stable until vial 7.
  
  
  CONCLUSIONS
  Thus, our data suggest that Fe(2+) can be effective on inhibition of dissolution of enamel and that this effect may be durable.
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Al. Octávio Pinheiro Brisolla, 9-75 Bauru, SP 17012-901, Brazil. mbuzalaf@fob.usp.br
authors.forename: Marília Afonso Rabelo
authors.initials: MA
authors.lastname: Buzalaf
authors.forename: Flávia
authors.initials: F
authors.lastname: de Moraes Italiani
authors.forename: Melissa Thiemi
authors.initials: MT
authors.lastname: Kato
authors.forename: Cleide Cristina Rodrigues
authors.initials: CC
authors.lastname: Martinhon
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Magalhães
mesh_terms: D019342:Acetic Acid / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000818:Animals; D002327:Cariostatic Agents / Q000494:pharmacology*; D002417:Cattle; D003743:Dental Enamel / Q000187:drug effects; D003747:Dental Enamel Solubility / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007501:Iron / Q000494:pharmacology*; D017001:Tooth Demineralization / Q000517:prevention & control*
chemical_list: D002327:Cariostatic Agents; D007501:Iron; D019342:Acetic Acid