Effect of iron on bovine enamel and on the composition of the dental biofilm formed “in situ”
Accepted 14 October 2005.
Summary
Objectives
This study investigated in situ the effect of iron (Fe) on the reduction of demineralization of bovine enamel, as well as on the composition of dental biofilm.
Design and methods
Twelve volunteers were included in this blind crossover study, which was conducted in two stages of 14 days each. For each stage, the volunteers received palatal appliances containing four blocks of bovine enamel (4mm×4mm×2.5mm). Six volunteers dripped a solution of 15mmolL−1 ferrous sulphate onto the fragments and the remaining six dripped deionized water (eight times per day). After five minutes, a fresh 20% (w/v) sucrose solution was dripped onto all enamel blocks. During the experimental period the volunteers brushed their teeth with non-fluoridated dentifrice. After each stage, the percentage of surface microhardness change (%SMHC) and area of mineral loss (ΔZ) were determined on enamel and the dental biofilm formed on the blocks was collected and analysed for F, P, Ca, Fe and alkali-soluble carbohydrates. The concentrations of F, Ca and Fe in enamel were also analysed after acid biopsies.
Results
There was a statistically significant increase in the P and Fe concentrations in the biofilms treated with ferrous sulphate (p<0.05), which was not observed for F, Ca and alkali-soluble carbohydrates. The group treated with ferrous sulphate had significantly lower %SMHC and ΔZ when compared to control (p<0.05).
Conclusions
These results showed that ferrous sulphate reduced the demineralization of enamel blocks and altered the ionic composition of the dental biofilm formed in situ.
aDepartment of Pediatric Dentistry, Orthodontics and Public Health, Bauru School of Dentistry, University of São Paulo, Al. Octávio Pinheiro Brisolla, 9-75 17012-901, Brazil
bDepartment of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Al. Octávio Pinheiro Brisolla, 9-75 Bauru-SP 17012-901, Brazil
cDepartment of Chemistry and Biochemistry, Biosciences Institute, Paulista State University, Caixa Postal 510, 18618-000 Botucatu-SP, Brazil
dDepartment of Pediatric Dentistry, Faculty of Dentistry of Araçatuba, Paulista State University, Araçatuba, Rua José Bonifácio, 1193 Araçatuba-SP 16015-050, Brazil
ABSTRACT