Neurological outcomes in children with and without amalgam-related mercury exposure: seven years of longitudinal observations in a randomized trial.
BACKGROUND
Although large-scale, randomized trials involving children have been completed and their results demonstrate an absence of neurobehavioral effects from clinical exposure to mercury amalgam, neurological findings from such studies have not been reported.


METHODS
The authors conducted a randomized, prospective trial examining the safety of dental amalgam in which 507 children aged 8 through 12 years were assigned to treatment with either amalgam or resin-based composite. During seven years of follow-up, the authors performed annual clinical neurological examinations, including an evaluation of neurological hard signs (NHSs), presence of tremor and neurological soft signs (NSSs).


RESULTS
The authors found no significant differences between treatment groups in any of the neurological measures. Groups did not differ with respect to the presence or absence of NHSs or tremor, nor the presence or absence or severity of NSSs at any point. As expected, NSS severity scores diminished with increasing age.


CONCLUSIONS
Even at the levels of amalgam exposure in this study (a mean of 7.7-10.7 amalgam surfaces per subject across the seven years of follow-up), the authors conclude that exposure to mercury from dental amalgam does not adversely affect neurological status.


CONCLUSIONS
The current evidence is that potential neurobehavioral or neurological effects from dental amalgam mercury exposure in children are inconsequential.
Lauterbach
Martin
M
Laboratorio de Estudios de Linguagem, Faculty of Medicine, University of Lisbon, Portugal.
Martins
Isabel P
IP
Castro-Caldas
Alexandre
A
Bernardo
Mario
M
Luis
Henrique
H
Amaral
Helena
H
Leitão
Jorge
J
Martin
Michael D
MD
Townes
Brenda
B
Rosenbaum
Gail
G
Woods
James S
JS
Derouen
Timothy
T
D002648:Child; D002652:Child Behavior; D002663:Child Language; D015331:Cohort Studies; D003188:Composite Resins; D003391:Cranial Nerves / Q000187:drug effects; D003723:Dental Amalgam / Q000737:chemistry; D003793:Dental Restoration, Permanent; D005260:Female; D005500:Follow-Up Studies; D005684:Gait / Q000187:drug effects; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008628:Mercury / Q000009:adverse effects*; D009048:Motor Skills / Q000187:drug effects; D053580:Muscle Strength / Q000187:drug effects; D009460:Neurologic Examination; D009949:Orientation / Q000187:drug effects; D011446:Prospective Studies; D012018:Reflex / Q000187:drug effects; D012449:Safety; D014202:Tremor / Q000139:chemically induced
D003188:Composite Resins; D003723:Dental Amalgam; D008628:Mercury