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Health Effects of Silver-Mercury Dental Fillings

This study has been completed.
National Institute of Dental and Craniofacial Research (NIDCR)
Information provided by (Responsible Party):
Timothy DeRouen, University of Washington Identifier:
First received: August 4, 2003
Last updated: March 20, 2017
Last verified: March 2017
The purpose of this study is to determine whether there are detectable health effects of low-level mercury exposure (from normal exposure to mercury-containing dental fillings) in the known target organs/systems affected by elemental mercury exposure.

Condition Intervention Phase
Caries, Dental
Device: Dental amalgam restorations
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (masked role unspecified)
Primary Purpose: Treatment
Official Title: The Casa Pia Study of the Health Effects of Dental Amalgam in Children.

Resource links provided by NLM:

Further study details as provided by University of Washington:

Primary Outcome Measures:
  • Memory
  • Rey Auditory Verbal Learning,
  • Finger Windows,
  • Visual Learning
  • Visual Motor Functions
  • Drawing, MatchingP
  • Pegboard sub-tests from the Wide Range Assessment of Visual Motor Abilities.
  • Attention/Concentration
  • Coding
  • Symbol Search
  • Digit Span
  • Standard Reaction Time
  • Stroop
  • Trails A and B.
  • Neurological: Nerve Conduction Velocity

Estimated Enrollment: 507
Study Start Date: August 1996
Study Completion Date: February 2011
Primary Completion Date: July 2005 (Final data collection date for primary outcome measure)
Detailed Description:
The Casa Pia Study of the Health Effects of Dental Amalgam in Children is a randomized, prospective clinical trial with the overall goal of determining if there are detectable health effects due to exposure from mercury-containing dental amalgam fillings. Children, thought to be the population most susceptible to any possible health effects, were randomly assigned to one of two treatment groups (total n=507). Subjects were originally enrolled at ages between 8-10 years of age. To participate, subjects must have: Dental caries in at least one posterior tooth; no prior exposure to dental amalgam; a blood lead of <15ug/L; a urinary mercury level of <10ug/L; an IQ as measured by the CTONI of >67; and no prior or existing serious medical or neurologic condition. One group received only dental filling materials other than those containing mercury (plastic and ceramic composites), while the other group received mercury amalgam fillings where appropriate (in large restorations in back teeth), but the alternative materials everywhere else. Both treatment regimens are standard-of-care throughout the world. Subjects receive ongoing dental care via the study clinics, and continue to receive dental fillings as needed based on group assignment. The target organs of mercury exposure are renal and neurological. Baseline and annual repeated measures are taken on all subjects for renal function, nerve conduction velocity and a large battery of neurobehavioral tests. Follow-up is planned for a period of 7 years

Ages Eligible for Study:   8 Years to 12 Years   (Child)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
  • Age 8-10 years of age
  • Dental caries in at least one posterior tooth.
  • No prior exposure to dental amalgam
  • Blood lead of <15ug/L
  • Urinary mercury level of <10ug/L
  • IQ as measured by the CTONI of >67
  • No prior or existing serious medical or neurologic condition
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Please refer to this study by its identifier: NCT00066118

United States, Washington
University of Washington, School of Dentistry
Seattle, Washington, United States, 98195
Sponsors and Collaborators
University of Washington
National Institute of Dental and Craniofacial Research (NIDCR)
Principal Investigator: Timothy DeRouen University of Washington
Study Chair: Michael Martin University of Washington
  More Information


Responsible Party: Timothy DeRouen, Professor Emeritus of Oral Health Sciences, School of Dentistry, University of Washington Identifier: NCT00066118     History of Changes
Obsolete Identifiers: NCT00000365
Other Study ID Numbers: 10085-A
U01DE011894 ( US NIH Grant/Contract Award Number )
95-0401-A 13 ( Other Identifier: UW Human Subjects Division )
Study First Received: August 4, 2003
Last Updated: March 20, 2017

Keywords provided by University of Washington:
nerve conduction
renal disease

Additional relevant MeSH terms:
Dental Caries
Tooth Demineralization
Tooth Diseases
Stomatognathic Diseases processed this record on May 24, 2017