title: Correlation between long-term in vivo amalgam restorations and the presence of heavy elements in the dental pulp.
abstract: METHODS
  To measure the levels of heavy metals (Hg, Sn) in the dental pulp and blood samples of patients with long-term amalgam restorations.
  
  
  METHODS
  12 amalgam restored and 12 non-restored, sound teeth were chosen and access cavity preparation to the pulp chamber was made. The contents were transferred and dissolved in 5mL of concentrated nitric acid followed by placement in an oven at 180°C for tissue digestion. After cooling the tubes each digested sample was transferred to an atomic absorption system to measure the levels of heavy metals. The blood samples of five patients in each group were randomly analyzed to determine the levels of these heavy metals in the blood and if there were a correlation between these levels in blood and pulp. Data were analyzed by t-test at a P<0.05 level of significance.
  
  
  RESULTS
  No significant difference was seen between the levels of Hg and Sn in pulp tissues (P>0.05); however, the blood analysis showed higher level of Hg amalgam group (P=0.009). The analysis between the pulp and blood samples showed positive correlations for both Hg and Sn elements in dental pulp and the blood (P=1.000) (P=0.900).
  
  
  CONCLUSIONS
  The long-term presence of dental amalgam (at least 5 years) did not result in any remarkable changes in the levels of mercury and tin in the pulp tissue; however, there were increases in the level of mercury in the blood circulation even five years following the placement of the restoration.
authors.affiliation: Department of Dental Material, Dental School, Azad University (Tehran Branch), Tehran, Iran. Electronic address: saghiri@gmail.com.
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Saghiri
authors.affiliation: Department of Dental Material, Dental School, Azad University (Tehran Branch), Tehran, Iran.
authors.forename: Sepideh
authors.initials: S
authors.lastname: Banava
authors.affiliation: Department of Dental Material, Dental School, Azad University (Tehran Branch), Tehran, Iran.
authors.forename: Mohamad Amin
authors.initials: MA
authors.lastname: Sabzian
authors.affiliation: Department of Restorative Sciences, Baylor College of Dentistry, Texas A&M University System Health Science Center, Dallas, TX, USA.
authors.forename: James L
authors.initials: JL
authors.lastname: Gutmann
authors.affiliation: Kamal Asgar Research Center (KARC), Tehran, Iran.
authors.forename: Armen
authors.initials: A
authors.lastname: Asatourian
authors.affiliation: Department of Pedodontist, Azad University (Tehran Branch), Tehran, Iran.
authors.forename: Golam H
authors.initials: GH
authors.lastname: Ramezani
authors.affiliation: Bioscience Research Center, College of Dentistry, University of Tennessee Health Science Center, Memphis, TN, USA.
authors.forename: Franklin
authors.initials: F
authors.lastname: Garcia-Godoy
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
authors.forename: Nader
authors.initials: N
authors.lastname: Sheibani
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003723:Dental Amalgam / Q000378:metabolism*; D003782:Dental Pulp / Q000378:metabolism*; D003793:Dental Restoration, Permanent; D006801:Humans; D008628:Mercury / Q000032:analysis* / Q000097:blood; D013997:Time Factors; D014001:Tin / Q000032:analysis* / Q000097:blood; D055815:Young Adult
chemical_list: D014001:Tin; D003723:Dental Amalgam; D008628:Mercury
keywords: Dental Amalgam; Dental pulp; Mercury; Silver; Tin