We updated the design of this site on December 18, 2017. Learn more.
ClinicalTrials.gov Menu

Health Effects of Silver-Mercury Dental Fillings

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT00066118
Recruitment Status : Completed
First Posted : August 5, 2003
Last Update Posted : March 22, 2017
Information provided by (Responsible Party):

Study Description
Brief Summary:
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 or disease Intervention/treatment Phase
Caries, Dental Device: Dental amalgam restorations Phase 3

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

Study Design

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 507 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single
Primary Purpose: Treatment
Official Title: The Casa Pia Study of the Health Effects of Dental Amalgam in Children.
Study Start Date : August 1996
Primary Completion Date : July 2005
Study Completion Date : February 2011

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Mercury
U.S. FDA Resources

Arms and Interventions

Outcome Measures

Primary Outcome Measures :
  1. Memory
  2. Rey Auditory Verbal Learning,
  3. Finger Windows,
  4. Visual Learning
  5. Visual Motor Functions
  6. Drawing, MatchingP
  7. Pegboard sub-tests from the Wide Range Assessment of Visual Motor Abilities.
  8. Attention/Concentration
  9. Coding
  10. Symbol Search
  11. Digit Span
  12. Standard Reaction Time
  13. Stroop
  14. Trails A and B.
  15. Neurological: Nerve Conduction Velocity

Eligibility Criteria

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): 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
ClinicalTrials.gov Identifier: NCT00066118     History of Changes
Obsolete Identifiers: NCT00000365
Other Study ID Numbers: 10085-A
U01DE011894 ( U.S. NIH Grant/Contract )
95-0401-A 13 ( Other Identifier: UW Human Subjects Division )
First Posted: August 5, 2003    Key Record Dates
Last Update Posted: March 22, 2017
Last Verified: March 2017

Keywords provided by Timothy DeRouen, University of Washington:
nerve conduction
renal disease

Additional relevant MeSH terms:
Dental Caries
Tooth Demineralization
Tooth Diseases
Stomatognathic Diseases