title: Effect of extremely low frequency magnetic field on enamel microhardness in rats.
abstract: OBJECTIVE
  The potential effects on human health of extremely low frequency magnetic field (ELF-MF) are of considerable  concern. In the present study, it was investigated the effect of long term ELF-MF exposure on microhardness of rat teeth.
  
  
  METHODS
  Thirty male Sprague-Dawley rats were divided into three groups. The first and second  experimental groups (n=10) were exposed to 100 μT and 500 μT ELF-MF during 10 months, 2 hours a day  respectively. For the control group, nothing was applied to the rats and they completed their life cycle in the cage during the  study period. After ELF-MF exposure, microhardness of enamel surface was determined for each group.
  
  
  RESULTS
  The  decrease in microhardness in the second experimental group was found to be statistically significant compared to the  control group (P <0.05). However, no statistical difference was found between the first and second experimental groups (P  >0.05).
  
  
  CONCLUSIONS
  From the results it can be concluded that 500 μT level of magnetic field strengths may have a  certain negative effect on enamel mineralisation. Further investigations are necessary to analyse the effect of ELF-MF on  teeth.
authors.affiliation: Department of Paediatric Dentistry, Marmara University, Istanbul, Turkey. bkargul@marmara.edu.tr
authors.forename: B
authors.initials: B
authors.lastname: Kargul
authors.forename: I
authors.initials: I
authors.lastname: Yavuz
authors.forename: M Z
authors.initials: MZ
authors.lastname: Akdag
authors.forename: A
authors.initials: A
authors.lastname: Durhan
mesh_terms: D000818:Animals; D003743:Dental Enamel; D006244:Hardness; D060526:Magnetic Fields / Q000009:adverse effects*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014074:Tooth Calcification