title: Long term changes in health complaints after removal of amalgam restorations.
abstract: OBJECTIVE
  Concerns over adverse effects of mercury released from dental amalgam sometimes lead patients to request removal of their amalgam restorations. Several studies report improvement of subjective health after removal of amalgam restorations, but the mechanisms are unclear. The aim of this paper is to present data on long term changes in intensity of health complaints after amalgam removal in a group of patients with health complaints self-attributed to dental amalgam. Data from the five years follow-up in a clinical trial are presented and related to potential determinants of change.
  
  
  METHODS
  Patients previously referred to a specialty unit for health complaints attributed to amalgam restorations were included in the study. The 20 participants who were allocated to the treatment group had all amalgam restorations removed and replaced with other dental restorative materials. Intensity of health complaints was calculated from questionnaire data and personality variables were measured by MMPI-2.
  
  
  RESULTS
  At the follow-up five years after the amalgam removal was completed, intensity of general health complaints was significantly reduced (p=.001), but the symptom load was still high. The reduction was significantly correlated with concentration of mercury in urine at pre-treatment. There were no significant correlations with personality variables.
  
  
  CONCLUSIONS
  Removal of amalgam restorations was followed by a long term reduction of general health complaints, which was associated with mercury concentration in urine before amalgam removal. Additional studies are needed to confirm the potential mechanisms for the observed reduction.
authors.affiliation: a Dental Biomaterials Adverse Reaction Unit, Uni Research , Bergen , Norway.|b Department of Clinical Dentistry, Faculty of Medicine and Dentistry , University of Bergen , Bergen , Norway.
authors.forename: Lars
authors.initials: L
authors.lastname: Björkman
authors.affiliation: b Department of Clinical Dentistry, Faculty of Medicine and Dentistry , University of Bergen , Bergen , Norway.
authors.forename: Therese T
authors.initials: TT
authors.lastname: Sjursen
authors.affiliation: c Department of Biological and Medical Psychology, Faculty of Psychology , University of Bergen , Bergen , Norway.
authors.forename: Knut
authors.initials: K
authors.lastname: Dalen
authors.affiliation: a Dental Biomaterials Adverse Reaction Unit, Uni Research , Bergen , Norway.
authors.forename: Gunvor B
authors.initials: GB
authors.lastname: Lygre
authors.affiliation: a Dental Biomaterials Adverse Reaction Unit, Uni Research , Bergen , Norway.
authors.forename: Trine Lise L
authors.initials: TL
authors.lastname: Berge
authors.affiliation: a Dental Biomaterials Adverse Reaction Unit, Uni Research , Bergen , Norway.
authors.forename: Johanna
authors.initials: J
authors.lastname: Svahn
authors.affiliation: a Dental Biomaterials Adverse Reaction Unit, Uni Research , Bergen , Norway.
authors.forename: Birgitte F
authors.initials: BF
authors.lastname: Lundekvam
mesh_terms: D000328:Adult; D003723:Dental Amalgam / Q000009:adverse effects*; D017005:Dental Debonding; D003793:Dental Restoration, Permanent / Q000009:adverse effects*; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008628:Mercury / Q000097:blood; D008630:Mercury Poisoning / Q000517:prevention & control*; D008875:Middle Aged
chemical_list: D003723:Dental Amalgam; D008628:Mercury
keywords: Dental amalgam; mercury; personality tests; subjective health complaint