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Dental Amalgam: A Scientific
Review and Recommended Public Health Service Strategy for
Research, Education and Regulation
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Final Report of the
Subcommittee on Risk Management of
the Committee to Coordinate Environmental Health and
Related Programs
Public Health Service
January 1993
Department of Health and Human
Services
Public Health Service
Table of Contents
Introductory
letter from James O. Mason, M.D., Dr.P.H., Assistant
Secretary for Health
Introductory letter from
James S. Benson, Chairman, subcommittee on Risk
Management
Members
of the Subcommittee on Risk Management
Preface
Perspectives
on Dental Caries Prevention and Tooth Restorations
Highlights of the
Report
Amalgam Use and
Benefits
Amalgam Risks
Alternatives
Selection
of a Dental Restorative Material
Policies on Dental
Amalgam
Research
Education
Regulation
Recommended PHS
Strategy
Contributors to
the Report
APPENDICES
I: The Benefits of Dental
Amalgam
II: Summary Tables on the
Advantages and Disadvantages of Alternative Dental
Restorative Materials
III: Evaluation of Risks
Associated With Mercury Vapor from Dental Amalgam
IV: Research Work Group
Report
V: Education Work Group
Report
VI: Regulatory Work Group
Report
VII: Government and
Professional Organization Policy Statements on Dental
Amalgam and PHS Position Paper - Environmental
Contamination from Mercury: Relationship to
Recommendations Concerning Amalgam Use in Europe
and United States
VIII: Potential
Biological Consequences of Mercury Released From Dental
Amalgam
James
O. Mason, M.D., Dr.P.H.
Assistant Secretary for Health
DEPARTMENT OF HEALTH & HUMAN SERVICES
Public Health Service
January 15, 1993
Office of the Assistant Secretary for Health
Washington, DC 20201
Over the past two years, scientists and public health
experts from the U.S. Public Health Service (PHS), the
Environmental Protection Agency, and the health care and
academic sectors have examined the question of whether
mercury-containing amalgam used in clinical dentistry
produces adverse health effects.
The enclosed report is the end product of their
in-depth analysis. It contains the latest scientific
information on the risks and benefits associated with
dental amalgam, and a multi-faceted strategy to which
the PHS is fully committed for further addressing this
issue. The report also reaffirms the position enunciated
by the PHS in March 1991, which stated that "there
are no data to compel a change in the current use of
dental amalgam."
Because the possibility of adverse health effects
resulting from the use of dental amalgam cannot be fully
discounted based on available scientific evidence, I am
requesting the PHS agencies to carry out an expanded and
targeted research effort. We welcome any thoughts or
comments you might have on this report. You may direct
your written views to the Subcommittee on Risk
Management/CCEHRP, 5600 Fishers Lane (HFZ-1), Rockville,
MD 20857.
Sincerely, James O. Mason, M.D., Dr.P.H.
Assistant Secretary for Health
James S.
Benson
Chairman Subcommittee on Risk Management
DEPARTMENT OF HEALTH & HUMAN SERVICES
Public Health Service
October 1, 1992
James O. Mason, M.D., Dr.P.H.
Assistant Secretary for Health and
Chairman, Committee to Coordinate Environmental Health
and Related Programs
U.S. Public Health Service
Washington, D.C. 20201
Dear Dr. Mason:
In 1991, you directed the CCEHRP to prepare a
scientific review of the risks and benefits of dental
amalgam, the most commonly used restorative material in
dental practice. Upon completion of that review, you
directed the Subcommittee on Risk Management to
formulate a strategic plan for addressing continuing
concerns about amalgam safety. Our work was predicated
on the reports presented to CCEHRP by the Subcommittee
on Risk Assessment and the Ad Hoc Subcommittee on the
Benefits of Dental Amalgam.
Our objective was to prepare a coherent, broad-based
plan for enhancing risk definition, for helping dental
patients and providers put amalgam risks and benefits
into perspective through targeted educational
initiatives, for identifying important research
questions, and for ensuring adequate Federal regulatory
oversight of this product. This report outlines a plan
of action that addresses each of these areas and
suggests the PHS agencies that are best suited to
implement the various tasks.
I am pleased to present the enclosed report to you
and the full Committee for consideration. I should
inform you that the report has undergone extensive
review by a number of groups, including CCEHRP's
Subcommittees on Risk Management, Risk Assessment, Risk
Communication and Education, Research Needs, and the Ad
Hoc Subcommittee on the Benefits of Dental Amalgam. It
has also been subjected to outside scientific peer
review by experts from the fields of dentistry,
toxicology and risk assessment.
I trust you and the members of CCEHRP will find this
report useful.
Sincerely yours,
James S. Benson
Chairman Subcommittee on Risk Management
Members
of the Subcommittee on Risk Management
James S. Benson, Chairman*
Director
Center for Devices and Radiological Health, FDA
Michael C. R. Alavanja, Dr. P.H.
Special Assistant for Epidemiology and Biostatistics
National Cancer Institute, NIH
Catherine W. Carnevale, D.V.M.
Assistant to the Director
Center for Food Safety and Applied Nutrition, FDA
Ronald P. Coene
Deputy Director (Washington Operations)
National Center for Toxicological Research, FDA
Brian W. Flynn, Ed.D.
Emergency Services Coordinator
National Institute of Mental Health, ADAMHA
Bryan D. Hardin, Ph.D.
Assistant Director
National Institute for Occupational Safety and Health,
CDC
Ronald M. Johnson
Director
Office of Compliance and Surveillance
Center for Devices and Radiological Health, FDA
Barry L. Johnson, Ph.D.
Assistant Administrator
Agency for Toxic Substances and Disease Registry
Gene W. Matthews, J.D.
Legal Advisor to CDC and ATSDR
Office of General Counsel, CDC
Richard W. Niemeier, Ph.D.
Director
Division of Standards Development and Technology
Transfer
National Institute of Occupational Safety and Health,
CDC
Bernard A. Schwetz, D.V.M., Ph.D.
Chief, Systems Toxicity Branch
National Institute for Environmental Health Sciences,
NIH
Allan S. Susten, Ph.D., DABT
Chief, Technical Support Section
Agency for Toxic Substances and Disease Registry
*[Editors note: Since December 16, 1992, Dr.
Elizabeth D. Jacobson, Acting Director, Center for
Devices and Radiological Health, FDA, has served as
Acting Chair of the Subcommittee on Risk Management.]
Preface
In 1989, the National Research Council (NRC)
published "Improving Risk Communication," a
report spawned by an earlier study on risk assessment in
the Federal government. In the report, the NRC defines
"risk management" as "a term used to
describe processes surrounding choices about risky
alternatives." Risk management, according to the
NRC, is the endpoint response following assessment of
the risks and benefits of specific hazards.1
One potential hazard that has captured substantial
attention is the use of dental amalgam to treat dental
caries Some scientists and patient advocacy groups have
voiced concern about the potential dangers arising from
mercury vapor from amalgam restorations. Media stories
have further heightened consumer concern. In 1991, an
American Dental Association survey of 1000 American
adults revealed that nearly half believed that health
problems could develop from dental amalgam.2
Also in 1991, the National Institutes of Health (NIH)
and the Food and Drug Administration (FDA) separately
convened panels of experts to evaluate the current state
of knowledge regarding amalgam-related hazards and
render professional opinions about the safety of this
product. In both cases, the experts agreed that current
research information does not demonstrate a causal
relationship between dental amalgam and a human health
detriment.3 In addition, the U.S. Public
Health Service, at the direction of the Assistant
Secretary for Health, brought together risk assessment
and benefits independent judgment about the degree of
health risk, if any, posed by amalgam use. They, too,
determined that current research data do not demonstrate
a health hazard for the vast majority of individuals
exposed to mercury vapor at levels commonly encountered
from dental amalgam. However, these groups have
recommended more research before the possibility of
amalgam-caused risks, as well as possible risks that may
result from the use of alternative materials, can be
dismissed.
At a February 1992 symposium on the toxicity of
mercury vapor from dental amalgam, held under the
auspices of the Society of Toxicology, experts agreed
that more remains to be learned about the effects of
chronic, low-level mercury exposure associated with
amalgam. Attendees agreed on the need for the
development of new and sensitive biomarkers of exposure
and toxicity. They also called for more research in the
areas of neurologic, reproductive, developmental and
renal effects, and the mechanisms that underlie them.
Finally, the participants encouraged investigation into
autoimmune-mediated renal injury induced by mercury.4
Also last year, the Swedish Medical Research Council
held a scientific conference on the biological
consequences of mercury released from dental amalgam. A
June 1992 Council report (see Appendix VIII) on the
conference concluded that "mercury released from
dental amalgam does not, according to available data,
contribute to systemic disease or systemic toxicological
effects" or "give[ s] rise to teratological
effects."
In response to growing concern about amalgam safety,
which predated many of these events, the Assistant
Secretary for Health—acting in his capacity as
Chairman of the PHS
Committee to Coordinate Environmental Health and
Related Programs— directed that a risk management plan
be developed. In broad concept, the plan was to address
research needs, taking into account research studies now
underway to quantify potential health risks from mercury
in dental amalgam. The plan was also to outline possible
educational messages and programs for putting amalgam
risks into perspective and to identify options for
increased regulatory oversight of this product.
This report responds to that charge. This report is
not intended to serve as the authoritative source on
dental amalgam safety, but rather as a planning tool to
assist policy-makers in deciding on appropriate risk
management actions.
References
1 Improving Risk Communication, Committee on
Risk Perception and Communication / National Research
Council. National Academy Press, Washington, D.C. -
1989. pg. 37. 1 Improving Risk Communication, Committee
on Risk Perception and Communication / National Research
Council. National Academy Press, Washington, D.C. -
1989. pg. 37.
2 ADA News. April 8,1991. pg.3. 2 ADA News.
April 8,1991. pg.3.
3 "Effects and Side-Effects of Dental
Restorative Materials." An NIH Technology
Assessment Conference, National Institute of Dental
Research, Bethesda, Maryland, August 26-28, 1991. In
Advances in Dental Research, Volume 6, 1992. 3
"Effects and Side-Effects of Dental Restorative
Materials." An NIH Technology Assessment
Conference, National Institute of Dental Research,
Bethesda, Maryland, August 26-28, 1991. In Advances in
Dental Research, Volume 6, 1992.
4 Goering, P.L., et al. Symposium Overview.
Toxicity Assessment of Mercury Vapor from Dental
Amalgams. Fundamental and Applied Toxicology. 4 Goering,
P.L., et al. Symposium Overview. Toxicity Assessment of
Mercury Vapor from Dental Amalgams. Fundamental and
Applied Toxicology.
Perspectives
on Dental Caries Prevention and Tooth Restorations
The day is surely coming .... when we will be engaged
in practicing preventive, rather than reparative,
dentistry. When we will so understand the etiology and
pathology of dental caries that we will be able to
combat its destructive effects by systemic medication.
Dr. G. V. Black 1896
Much of Black's prediction has come true. Thus, there
is now a rational basis for prevention and treatment
that reflects the successes of dental research. Caries
is an infectious disease caused by acid-producing
bacteria in dental plaque. The old adage that "a
clean tooth never decays" is still valid.
Fluorides, both systemic through community water
fluoridation or prescribed supplements, and topicals
such as toothpaste, rinses and professionally applied
gels, dramatically reduce caries rates. Protective
sealants applied to the chewing surfaces of children's
permanent teeth reduce these rates further. Therefore,
there is every reason to expect that with concerted
effort, dental caries largely can be eliminated in
future generations and can be well-controlled among
Americans living today. This must be the fist
priority for the U.S. Public Health Service (PHS),
health care providers and the Nation.
In future years, the restoration of cavities will
cease to be the mainstay of general and pediatric
dentists. Treatments emphasizing conservative and
preventive approaches should be expected. New adhesives
and more durable plastic restorative materials that are
currently available allow for increasing use of
minimally invasive procedures that are more preventive
than restorative. Preventive rinses allow
remineralization of early lesions on tooth crowns and
roots and should be used increasingly. Caries in all its
forms, however, will continue to be seen in adults, the
elderly and populations at high risk of disease
regardless of age. In addition, there remain generations
of people with fillings that predate the preventive era.
Large, oversized replacement restorations and durable,
effective restorative materials will be required for
this group for many years to come.
The PHS is committed to disease prevention and health
promotion and is trying to assure proper access to
necessary diagnostic, preventive and clinical services
for those segments of the populations most susceptible
to disease. This goal is embodied in Healthy People
2000: National Health Promotion and Disease Prevention
Objectives, and includes sixteen oral health
objectives. These objectives, to be achieved by the year
2000, target reductions in oral diseases such as caries,
as well as increased use of proven preventive therapies
or practices, the most important being community water
fluoridation and dental sealants.
Although this report addresses the use of important
dental restorative materials, fist priority should be
placed on the conservation of healthy teeth through the
use of available preventive therapies. This would limit
the use of any restorative material. The best
restoration is the one that is never needed. When teeth
can be kept sound, there are no concerns over longevity,
toxicity, or the esthetics of restorative materials. The
all-important achievement will be oral health for all
and preservation of natural teeth for a lifetime.
Highlights of the
Report
 | Dental amalgam has been used as a dental
restorative material for over 150 years. Amalgam
remains popular because it is strong, durable and
relatively inexpensive. Roughly half of the 200
million restorative procedures performed in 1990
utilized amalgam. Nonetheless, amalgam use is
declining because the incidence of caries is
decreasing and because improved substitute materials
are now available for certain applications. |
| Dental amalgam, an inter-metallic compound,
contains elemental mercury that is emitted in minute
amounts as vapor. Because vapor emitting from
amalgam restorations can be absorbed by the patient
through inhalation, ingestion, or other means,
concerns have been raised about possible toxicity.
At present, there is scant evidence that the health
of the vast majority of people with amalgam is
compromised, nor that removing amalgam fillings has
a beneficial effect on health. It also is recognized
that a total conversion from dental amalgam to
alternative materials would cause a significant
increase in U.S. health care costs. Nonetheless, the
possibility that this material, as well as currently
available alternatives, could pose health risks
cannot be totally ruled out because of the paucity
of definitive human studies. |
| Given the limitations of existing scientific data,
a research program should be designed and
implemented to fill as many gaps as possible in
current knowledge about the potential long-term
biological effects of dental amalgam and alternative
restorative materials. The PHS should be a leader in
this effort. |
| The PHS should also educate dental personnel and
consumers about the risks and benefits of dental
amalgam. An educational program should include
information on all restorative materials to help
dentists and their patients make informed dental
treatment decisions, and encourage dental care
providers to report adverse reactions. Such a
program should promote the use of preventive
measures such as fluoride and dental sealants to
prevent caries and thus further reduce the need for
dental restorations. |
| To exert greater control over dental amalgam use,
the FDA should regulate elemental mercury and dental
alloy as a single product. To help dentists identify
patients who may exhibit allergic hypersensitivity
to all restorative materials, including dental
amalgam, FDA should require manufacturers to
disclose the ingredients of these materials in
product labeling. |
| Sweden, Denmark and Germany have proposed
restrictions on dental amalgam use. They have done
so in an effort to diminish both human exposure to
and environmental release of mercury and not because
of any documented health effects associated with
exposure to dental amalgam. |
| The U.S. Public Health Service believes it is
inappropriate at this time to recommend any
restrictions on the use of dental amalgam, for
several reasons. First, current scientific evidence
does not show that exposure to mercury from amalgam
restorations poses a serious health risk in humans,
except for an exceedingly small number of allergic
reactions. Second, there is insufficient evidence to
assure the public that components of alternative
restorative materials have fewer potential health
effects than dental amalgam, including allergic-type
reactions. Third, there are significant efforts
underway in the U.S. to reduce the amount of mercury
in the environment. And finally, as stated
previously, amalgam use is declining due to a
lessening of the incidence of dental caries and the
increasing use of alternative materials. |
Amalgam Use and
Benefits
Before one can enter into a discussion about the use
of dental amalgam restorative materials, it is necessary
to consider the conditions for use, the criteria for an
optimal restorative material, and factors that would
influence the success of the material.
Dental amalgam, in widespread use for over 150 years,
is one of the oldest materials used in oral health care.
Its use extends beyond that of most drugs, and is
predated in dentistry only by the use of gold. Dental
amalgam is the end result of mixing approximately equal
parts of elemental liquid mercury (43 to 54 percent) and
an alloy powder (57 to 46 percent) composed of silver,
tin, copper, and sometimes smaller amounts of zinc,
palladium or indium.
Because of a general decline of dental caries among
school children and young adults, the use of dental
amalgam began to decrease in the 1970s. There are also
changes in patterns of dental caries, largely the result
of topical and systemic fluoride, sealant use, improved
oral hygiene practices and products and possibly dietary
modifications. In 1990, over 200 million restorative
procedures were provided in the United States; of these,
dental amalgam accounted for roughly 96 million, a 38
percent reduction since 1979. This trend is expected to
continue.
There are also reports that carious lesions today are
generally smaller, easier to treat, and managed by more
conservative treatment that retains tooth structure.
Because of this decrease in the frequency and size of
dental caries, there has been a relative increase in the
use of alternative dental restorative materials. The
most commonly used and less expensive of the alternative
materials, however, cannot be used for large lesions and
need more frequent replacement. Also, there are
currently many serviceable dental amalgam restorations
that will need replacing in the future. Approximately 70
percent of the restorations placed annually are
replacements. Most of these replacements will require
amalgam or other metallic materials, because composite
materials often lack sufficient strength or durability
to be considered adequate substitutes.
Today, dental amalgam is used in the following
situations:
| in individuals of all ages, |
| in stress-bearing areas and in small-to-moderate
sized cavities in the posterior teeth, |
| when there is severe destruction of tooth
structure and cost is an overriding consideration, |
| as a foundation for cast-metal, metal-ceramic and
ceramic restorations, |
| when patient commitment to personal oral hygiene
is poor, |
| when moisture control is problematic with
patients, and |
| when cost is an overriding patient concern. |
It is not used when:
| esthetics are important, such as in the anterior
teeth and in lingual endodontic-access (root canal)
restorations of the anterior teeth, |
| patients have a history of allergy to mercury or
other amalgam components, and |
| a large restoration is needed and the cost of
other restorative materials is not a significant
factor in the treatment decision. |
There are unique characteristics to dental amalgam
that appear to enhance its use, just as there are
characteristics that discourage its use (Table 1).
For additional information, see The Benefits of
Dental Amalgam report in Appendix I.
The use and attributes of alternative dental
restorative materials are discussed in the Alternatives.
Amalgam Risks
Dental amalgam can release minute amounts of
elemental mercury, a heavy metal whose toxicity at high
intake levels (such as in industrial exposures) is
well-established. Under the aegis of the PHS Committee
to Coordinate Environmental Health and Related Programs,
the Subcommittee on Risk Assessment performed a
comprehensive review of existing information on the
uptake of mercury from dental amalgam. (For details,
consult the Evaluation of Risks Associated with Mercury
Vapor From Dental Amalgam in Appendix III) The
Subcommittee concentrated on the toxicity of mercury,
looking in particular for evidence of biological effects
from the low doses to which patients might be exposed
from amalgam.
It is clear from the Subcommittee's review that a
fraction of the mercury in amalgam is absorbed by the
body; people with amalgam have higher concentrations of
mercury in various tissues (including blood, urine,
kidney and brain) than those without amalgam. Also, a
small proportion of individuals may manifest allergic
reactions to these restorations.
Mercury is absorbed from many sources, including food
and ambient air. Thus, it is not known whether the vast
majority of people with amalgam experience any clinical
effect from this small additional body burden of
mercury—and this is the key question which must be
answered in order to resolve the issue of whether
amalgam poses a public health risk.
Part of the reason for the dearth of information on
whether there are health effects from the mercury in
amalgam is that the few human studies that have
investigated this issue have been too small or flawed in
design to detect an effect. To add to the difficulty, if
there were long-term effects from the mercury in
amalgam, it is likely that they would be subtle in
nature—slight neurological or behavioral changes, for
example—and thus would be very difficult to detect and
assess in human populations. An alternative approach
would be to extrapolate from the effects known to occur
after high doses of mercury (such as those received from
poorly controlled occupational exposure) in order to
predict whether biological effects might occur after low
doses (such as those received from dental amalgam). But
the nature of the dose-response relationship for mercury
toxicity is not well enough understood to permit this.
In the absence of adequate human studies, the
Subcommittee on Risk Assessment could not conclude with
certainty whether or not the mercury in amalgam might
pose a public health risk; on the one hand, there is no
evidence at present that the health of people with
amalgam is compromised in any way. Likewise, there is no
evidence that removing amalgam has a beneficial effect
on health, despite anecdotal reports of
"improvement" after amalgam removal in
patients with certain chronic illnesses. (It should also
be noted that the removal process itself may expose the
patient to additional mercury, and that alternative
dental restorative materials could have long-term
toxicity problems of their own.) On the other hand,
given that the evaluation of potential health effects
from dental restorative materials, including dental
amalgam, will be an ongoing process, the possibility
that these materials could pose health risks cannot be
ruled out.
It is important to view mercury exposure from dental
amalgam in the context of other sources of mercury.
Table 11 of the report by the Subcommittee on Risk
Assessment (in Appendix III), puts the issue into
perspective by comparing several sources of mercury
exposure.
Alternatives
Besides dental amalgam, there are many other
restorative materials that are used in dentistry. These
materials have not been as effective as dental amalgam
in providing a durable and long-lasting restoration,
especially in larger lesions. However, advances in
technology have resulted in improvements that have
expanded their use. The following presents a comparison
of these materials. For a full discussion of the
advantages and disadvantages of each of the alternative
materials discussed in this section, refer to the
Benefits Report in Appendix I and a series of summary
tables provided in Appendix II.
Composites
The public is familiar with the use of composites as
esthetic restorations in the anterior teeth. Recent
improvements in the materials have resulted in increased
uses in the nonstress-bearing areas of the posterior
teeth. Currently, dentists are using a combination of
composites and sealants (preventive resin restorations)
to treat incipient (small) lesions and thereby conserve
tooth structure. Some dentists may advocate composites
for individuals who are concerned about dental amalgam.
This use of composites as substitutes for restorations
in stressbearing areas may be inappropriate. Composites
have other inherent limitations; specifically, their
sensitivity to moisture requires precise techniques on
the part of the dentist and their lack of resistance to
chewing stress may compromise their durability.
Composites are used in:
| small to moderately sized lesions in the posterior
teeth with no or little stress-bearing forces, |
| small to moderately sized anterior restorations, |
| repairs of porcelain crowns, |
| situations where a preventive resin is needed, and |
| foundations for metal, ceramic and cast-metal
restorations. |
In contrast, dentists generally do not use composites
when:
| restorations are required for stress-bearing
posterior teeth, since the wear factor will be
great, and |
| moisture control is poor. |
Pit and Fissure
Sealants
Sealants prevent dental caries by sealing the pits
and fissures of posterior teeth. Since pits and fissures
of permanent first molars account for 91 percent of the
carious surfaces in children up to 11 yeas of age,
sealants are an appropriate choice (see Appendix I for
details). However, the use of sealants as a treatment
strategy to preserve healthy tooth structure is still
not widespread. The 1989 National Center for Health
Statistics' Health Interview Survey found that 13 and 17
percent of 8 and 14 year olds, respectively, were
reported to have received sealants.
Preventive
Resin Restorations
Dentists use preventive resin restorations, a
combination of composites and sealants, to treat early
caries found in the pits and fissures. A dentist would
use this combination when the carious lesion extends
into and beyond the enamel so that the use of sealants
alone will not suffice. These restorations should only
be placed in the nonstress-bearing regions of the
dentition. Use of preventive resin restorations is
generally governed by the desire to treat small lesions
conservatively.
Glass lonomer
Glass ionomers were introduced to the dental
profession in the 1970s. Originally, their acceptance by
the dental community was limited because of problems
associated with manipulation of the material, setting
sequence, moisture sensitivity, less than expected
esthetic value and surface texture. Recently, dentists
are increasing their
use of glass ionomer because of the following
characteristics:
| the material chemically bonds to the tooth
structure and releases fluoride, |
| the placement technique is conservative, requires
minimal drilling and the patient response is
excellent, |
| the procedure is often quick, painless, and may
not require local anesthesia, and |
| the restoration is fairly esthetic. |
The limitations of the material include low tensile
strength, low impact and fracture resistance and
degradation qualities.
The recommended uses of this material are:
| to restore small to moderately sized cavities in
deciduous (baby) teeth, |
| as a cavity liner, |
| during caries control procedures, and |
| for restorations around the gum line (root
surface, caries, or abrasion). |
Glass ionomers are generally not used in:
| the occlusal surfaces of adult teeth, |
| stress-bearing restorations, and |
| situations where moisture control is difficult. |
Gold Foil
The various uses of gold foil date back many
centuries, although its use today is diminishing. Gold
foil restorations are noted for their longevity, lasting
up to 20 years if placed properly. Generally, this
material is not used for large restorations because of
its inability to withstand stress.
Gold foil restorations require great skill and
stringent attention to detail by the dentist during
placement. The trauma associated with placement may
result in potential damage to the pulp and/or
periodontal tissues. Because of the high cost associated
with gold foil and the limited number of applications,
this material is rarely used. In its place is an
increased use of the other improved alternative
materials.
Gold foil restorations are used for:
| incipient (small) cavities in nonstress-bearing
areas when esthetics is not a major concern, and |
| repair of endodontic (root canal) access openings
in gold crowns or for gold crown margins, inlays or
onlays. |
They are not used in:
| children and young adults, or |
| stress-bearing areas of the dentition. |
Cast
Metal and Metal-Ceramic Restorations
Cast metal and metal-ceramic restorations generally
require two or more appointments and are typically used
for inlays, onlays, crowns and/or bridges. The dentist
and the laboratory technician must pay close attention
to detail in each step of the process when using these
materials. The decision to use cast metal or
metal-ceramic restorations is dependent on the degree of
tooth destruction, the number of missing teeth, the
esthetic needs of the patient, the oral hygiene of the
patient and the patient's financial capability, since
these restorations cost approximately eight times more
than amalgam
Data about the longevity of noble metal (gold,
platinum, and palladium) inlays compared to amalgam
vary. One study found that the longevity of cast metal
restorations was almost 90 percent greater than that of
amalgam. The reported lifetime average for full metal
crowns was 10 years, with recurrent caries accounting
for 58 percent of the failures. Failures with these
types of restorations are a result of clinical
deficiencies, laboratory deficiencies, inadequate
communication between the dentist and laboratory
technician, technique sensitivity of the materials and
patient factors, such as poor oral hygiene.
These restorations are typically used in instances
when:
| high stress is expected in the targeted oral area, |
| moderate to severe breakdown of the natural tooth
requires cusp replacement, and |
| the patient demands an esthetic appearance rather
than conservative treatment (metal-ceramic). |
They are generally not used when:
| there is a danger of pulp exposure during tooth
preparation, for example, in patients under 18 years
of age, |
| patients exhibit evidence of extensive bruxing
and/or clenching when opposing natural teeth, and |
| there is documented allergy to the metals used in
casting alloys. |
Ceramic Restorations
The dental profession has embraced the use of this
material in recent years. Improvements in its
formulation resulted in a material with enhanced
physical properties. Consequently, porcelain and the
newer glass ceramics are increasingly used for
constructing artificial denture teeth, full crowns,
inlays, onlays, laminate veneers and the veneers found
over a metal substructure for crowns and bridges.
Although the improvements in this material have led to
the development of all-ceramic crowns, their most
appropriate use is limited to low stress-bearing areas.
Ceramic restorations are used for
| anterior crowns when esthetics cannot be assured
with the use of porcelain-fused-to-metal
restorations, |
| posterior teeth that are subjected to low biting
forces, and |
| patients for whom optimal esthetics is an
overriding concern. |
Ceramics are not typically used when:
| there is a danger of pulp exposure during tooth
preparation, for example, in patients under 18 yeas
of age, |
| the posterior areas are subjected to high biting
forces and in situations where
porcelain-fused-to-metal crowns cannot be used, |
| evidence exists of extensive bruxing and/or
clenching, and |
| the technician is inexperienced in using the
processing technique. |
Summary
of Selected Characteristics
Table 2 is a summary comparison of selected
characteristics of posterior restorative materials.
For additional details about the characteristics and
a complete discussion of all restorative materials,
consult the Benefits Report in Appendix I. This report
also contains a discussion of the biocompatibility of
restorative materials. The Report notes that
biocompatibility with local tissues is acceptable when
restorative materials are properly handled and placed.
Although there are reports of adverse systemic
reactions, generally allergic skin reactions, the
literature indicates that they are rare and
self-limiting, and tend to be allergenic in nature.
There are no reports of systemic toxic reactions. There
are documented reports of local reactions to amalgam,
composites and other restorative materials in a small
percentage of individuals. Additional details can be
found in the Benefits Report.
Table
2. Selected Characteristics of Posterior Restorative
Materials
|
Critical
Parameters in Evaluating Posterior Restorative
Materials |
AMALGAM |
COMPOSITE |
GLASS IONOMER |
GOLD FOIL
|
GOLD ALLOY (CAST) |
METAL-CERAMIC
CROWNS |
|
Median Longevity
Estimate1 |
8-12 years |
6-8 years when
used in conservative non-stress bearing situations |
No data:1
5 years predicted |
No data: 10-15
years estimated |
12-18 years |
12-18 years |
|
Relative Surface
Wear |
Wears slightly
faster than enamel |
Excessive wear in
stress-bearing situations |
Excessive wear in
stress-bearing situations |
Excessive wear in
stress-bearing situations |
Wears similar to
enamel |
Porcelain surface
may wear opposing tooth |
|
Resistance to
Fracture |
Fair to excellent |
Poor to excellent |
Poor |
Fair to good |
Excellent |
Excellent |
|
Marginal
Integrity (leakage) |
Fair to excellent
Self-sealing
through corrosion products |
Poor to excellent
Polymerization
shrinkage can cause poor margins |
Poor to excellent |
Poor to excellent |
Fair to good
Depends on fit
and type of luting agent used |
Poor to excellent
Depends on fit
and type of luting agent used |
|
Conservation of
Tooth Structure |
Good |
Excellent |
Excellent if
initial restoration, not if replacement |
Good |
Poor |
Poort |
|
Esthetics |
Poor |
Excellent |
Good |
Poor |
Poor |
Excellent |
|
Indications:
Age range
Occlusal stress
Extent of caries |
All ages
Moderate stress
Incipient to
moderate size cavity |
All ages
Low-stress-bearing
Incipient to
moderate size cavity |
All ages
Adult-Class V and
low-stress primary teeth
Class I and II
child Incipient to moderate size cavity |
Adult
Class III and V
and crown repair
Incipient to
moderate size cavity |
Adult
High-stress areas
Severe tooth
destruction |
Adult
High-stress areas
Severe tooth
destruction or esthetic considerations |
|
Cost to Patient2 |
1X |
1.5X |
1.4X |
4X |
8X + gold |
8X |
1 Longevity estimates reflect medians from
published studies; however, under different clinical
situation many restorations will last longer. For
materials which have emerged in the last decade and gold
foil, estimates are speculative. 1 Longevity estimates
reflect medians from published studies; however, under
different clinical situation many restorations will last
longer. For materials which have emerged in the last
decade and gold foil, estimates are speculative.
2 Relative cost to patient, in relation to
amalgam (1X). There may also be considerable geographic
variation. 2 Relative cost to patient, in relation to
amalgam (1X). There may also be considerable geographic
variation.
Selection
of a Dental Restorative Material
The selection of the type of dental restorative
material is dependent on many factors, among them the
characteristics of the tooth itself, the patient, the
dentist and the material. The dentist must make this
selection with great care because, in future years,
those restorations needing replacement will result in
the loss of increasing amounts of tooth structure. This
sets up a cycle where the increasing cavity size limits
the selection of the materials that may be used
effectively. There are numerous factors to consider when
restoring a tooth, e.g., the extent of the lesion, the
strength of the remaining tooth structure, the
preference of the dentist in using the material and the
financial cost of the procedure, both out-of-pocket
costs borne directly by the patient and those covered by
insurance. The Benefits Report (Appendix I) outlines
additional factors involved in this decision making
process. One of these factors is the additional costs of
substituting other materials for dental amalgam. All of
the alternative materials are more expensive than
amalgam on a one-time basis as well as over the lifetime
of an individual. The general use of the alternative
dental materials instead of amalgam will result in
markedly higher treatment costs. In fact, one model
predicts that totally discontinuing the use of dental
amalgam would increase costs by at least $12 billion the
first year with the likelihood of the cost increasing in
later years. Although the primary reason to restore a
tooth is dental caries, there are other clinical
situations that require restorations. Table 3 provides a
summary of these conditions and additional information
is contained in the Benefits Report.
In considering the characteristics of an ideal
restorative material, it is apparent that no single
material can fulfill all of the clinical needs. The
characteristics of the ideal restorative material are
described as fulfilling requirements applying to the:
| physical and mechanical properties of the
material, |
| technical features of the material from the
perspective of the dental professional, |
| patient factors of acceptability, and |
| other clinical aspects that contribute to the
material's effectiveness. |
The interaction of these factors determines the
longevity of the dental restoration. Figure 1
demonstrates the interaction of the three factors and
specifies the elements within each of these areas. (For
an in-depth discussion of the elements, see the Benefits
Report in Appendix I.)
Table 3. Indications, Treatment, and Restorative
Material Options for the Restoration of Posterior Teeth
|
Clinical Condition |
Preferred Treatment Options |
Dental Material Options |
| Questionable caries
-smooth surface, pit or fissure sticking |
Fluoride treatment;
oral hygiene instruction; seal pits and fissures
and/or observe and re-evaluate at recall
appointments |
Sealant |
| Incipient (early)
caries |
Preventive
resin/sealant |
Preventive
resin/sealant, composite, glass ionomer |
| Moderate to extensive
caries |
Restore or extract if
tooth destruction is extensive |
Amalgam, cast metal,
ceramic, metal-ceramic |
| Defective or failed
restoration |
Repair or replacement |
Depends on whether
restoration is being repaired or replaced, may
include any restorative material |
| Tooth fracture |
Restore or extract
depending upon severity |
Amalgam, composite,
cast alloys, metal-ceramic ceramics (depends on
severity of fracture) |
Figure 1. Factors Influencing the Success of a
Restoration
Policies on
Dental Amalgam
Development of national public health policy requires
consideration of both scientific research and
experiential data. It is often influenced by the views
of governmental and private health organizations with
specialized knowledge about a particular subject. It is
instructive, therefore, to examine the policy views that
exist on dental amalgam. This is a useful process in the
formulation of guidance to the nation's dental care
providers who look to the U.S. Public Health Service,
among others, for expert advice on known and potential
hazards and acceptable standards of practice. The policy
views of others can also serve as guideposts for policy
makers in the PHS who must decide on new program
initiatives and the priority and funding levels that
should be assigned to them.
Taken together, these policy statements reflect a
general consensus that appears to be supportable by the
latest scientific knowledge.
| "Current research on the use of silver dental
amalgam suggests that amalgam continues to
demonstrate clear advantages in many applications
over other restorative materials. Significant
evidence of patient risk associated with its use has
not been demonstrated. Most therapeutic materials
involve potential side effects or risks as well as
benefits and dentists are trained to be on their
guard for these reactions at all times." |
Canadian Dental Association, 1986
| "At present, there are no scientific data
indicating that exposure to mercury from dental
amalgam causes symptoms of poisoning. The National
Board of Health and Welfare's group of experts,
however, underlined that amalgam is an unsuitable
dental filling material from a toxicological point
of view. The development should be stimulated of new
dental filling materials which are technically and
biologically toxicologically satisfactory. While
waiting for such materials to become available as
general replacement for amalgam, amalgam may
therefore still be used as dental replacement
material. On the other hand, the Board of Health and
Welfare is of the opinion that treatment of pregnant
women with amalgam should be avoided as far as
possible. This judgment has been passed awaiting
further research into disorders of the reproductive
system related to exposure to mercury." |
National Board of Health and Welfare of Sweden, June
1988
| "Assuming that a minute amount of mercury may
be released from dental amalgams in humans, the
question remains as to how much is released and
absorbed and, more importantly, whether this amount
of mercury has any bearing on human health. Until
these questions are answered and we have reasonable
evidence that dental amalgams actually can be
handful to health, we cannot take action against
these products, particularly in light of the value
they provide in dental care." |
Food and Drug Administration, October 1990
| "Throughout its use, there has been
considerable scientific study of amalgam and no
documented evidence to support the contention that
amalgam, or the mercury contained in amalgam, has
any deleterious effect on the health or physical
well-being of the millions of patients served
throughout the world. The research currently
creating interest and controversy has been found by
the scientific community to have considerable
shortcomings in methodology and to be totally
inconclusive as to any detrimental health
ramifications for humans. Based on the research and
epidemiological evidence available to date, the ADA
continues to support dental amalgam as a safe and
effective restorative material and sees no cause for
public concern about either existing or future
amalgam restorations." |
American Dental Association, December 1990
| "Based on the available research, the NIDR
concludes that dental amalgam poses no known health
risk to individuals who are not hypersensitive to
the materials. At this time, there is no reason for
recommending either the discontinuation of dental
amalgam as restorative materials or the removal of
dental amalgam from patients who have no
demonstrated hypersensitivity to mercury or other
components of amalgam. |
National Institute of Dental Research, March 1991
| "At present and until additional information
under study dictates, there are no data that would
compel a change in the current use of dental
amalgam. When dentists are placing amalgam in teeth
or removing amalgam, they should carefully adhere to
guidelines developed for their use, and, to the
extent possible, limit exposure to mercury." |
U.S. Public Health Service, March 1991
| "Notwithstanding the mercury component of
silver amalgam, extensive reviews of the scientific
literature have not revealed any data published in
refereed scientific journals to support claims that
amalgam restorations have caused any adverse
biological reactions other than extremely rare
allergy to one of the amalgam components.
Replacement of silver amalgam restorations is not
justified except when the restoration has failed;
where it has fractured; where there is recurrent
dental caries at its margin; where access to the
dental pulp is needed; or where there is a
clearly-established case of mercury hypersensitivity
associated with clear evidence of an adverse effect
from an amalgam restoration." |
Federal Dentaire Internationale, June 1991
| "According to the latest status of scientific
knowledge, no reasonable suspicions that amalgam
fillings are hazardous to one's health can be
established from a medical point of view if one
considers the already existent burden of mercury
through a person's daily intake of mercury with
food, water, and air. Nevertheless, the use of
amalgams is to be decreased as much as possible in
order to reduce the strain on the human body caused
by general mercury intake. The Federal Public Health
Office does not recommend to substitute already
existing fillings by other filling materials, unless
the individual medical situation, e.g. an allergic
reaction, requires that. As already recommended in
1987 by the Federal Public Health Office, no major
dental procedures involving amalgams should be done
during pregnancy. Even though there are no reasons
to believe that amalgams could be hazardous to the
health of the unborn child, the Federal Health
Office asks to observe this recommendation in the
interest of preventive medicine." |
Federal Public Health Office of Germany, 1992
| "Although minute amounts of mercury are
released from amalgam restorations, these do not
cause demonstrable adverse effects of significance
to the general public. Published reports of systemic
toxic effects documented to have been caused by
mercury from dental amalgam, are not available in
the scientific literature. Local allergic reactions
are exceedingly rare, and when they occur, they can
be eliminated by the substitution with another
materiel. Available scientific evidence does not
justify the discontinuation of the use of amalgam,
nor does it endorse a clinical concept that
recommends the removal and replacement of
satisfactory amalgam fillings with other
materials." |
Swedish Medical Research Council, June 1992
During 1991-92, the U.S. Public Health Service
Committee to Coordinate Environmental Health and Related
Programs conducted a thorough assessment of the risks
and benefits associated with dental amalgam, including a
critical evaluation of the most current scientific
information. Based upon those reviews, the PHS reaffirms
its policy statement issued in March 1991 (as excerpted
above). A full discussion of the rationale for this
reaffirmation is discussed in Appendix VII of this
report.
U.S. Public Health Service, Committee to Coordinate
Environmental Health and Related Programs, December
1992.
Research
It was clear from the findings of the CCEHRP
Subcommittee on Risk Assessment that additional research
is needed to resolve the question of whether the mercury
in dental amalgam poses any significant health risk to
patients. The answer to this question would resolve the
two basic public health policy issues regarding dental
amalgam: whether amalgam restorations should continue to
be used in the future, and whether existing restorations
should be removed and replaced with other materials.
The Subcommittee on Risk Management (through an
interagency Research Work Group) was charged with
looking into several aspects of research on the health
effects of dental amalgam. These are the group's
conclusions:
| Research is needed on the specific health effects
of low-level mercury exposure; on the absorption,
distribution, metabolism and elimination of this
material; on potential biological markers for
exposure and effect; on the medical significance of
such markers; and on the significance of various
blood, urine or tissue levels of mercury. |
| Among the issues high on any dental amalgam
research agenda would be the following: whether
low-level mercury effects are prevalent in the
general population, and whether these can be
attributed to amalgam; which special population
groups, if any (e.g., children, pregnant women, or
those with renal disease), might be especially
sensitive to mercury effects; how human studies
could be designed to assess the potential effects of
dental amalgam; whether existing amalgam should be
replaced and, if so, under what circumstances; how
the mercury in amalgam might be stabilized to
minimize release into the body; and, how safe and
effective are the existing alternatives to amalgam. |
| The PHS should establish an intramural tracking
mechanism to identify and monitor amalgam research
projects which it funds. It should be administered
by the Office of the Assistant Secretary for Health,
and should also include information from relevant
sister agencies such as the Environmental Protection
Agency (EPA) and the Department of Defense (DOD), as
well as from the private sector. |
| The declining reliance on dental amalgam should be
encouraged by promoting the use of dental sealants
to prevent caries, and the use of alternative
materials for dental restorations where clinically
appropriate. |
| FDA’s medical device reporting programs are not
likely to be useful as a source of information for
definitive scientific amalgam research. These
reporting programs, although important to FDA as an
early-warning system on device adverse effects,
cannot quantify population risks and are often
subject to various biases which limit their
usefulness for research purposes. |
| The Research Work Group has compiled an inventory
of existing research studies that bear upon the
issue of amalgam safety (see Appendix IV). The Work
Group has also identified a series of scientific
questions which must be answered before a definitive
conclusion can be reached on amalgam safety. This
material, along with a prioritized list of research
areas compiled by the Work Group, can serve as a
basis for designing a targeted research program. |
Education
Over the past decade, the use of amalgam has declined
because of a decrease in dental caries and improvement
in alternative materials. Nevertheless, dental amalgam
continues to play an important role in the dental
restorative process. Recently, a number of public health
concerns regarding mercury in dental amalgam have been
raised. Although no controlled clinical studies have
shown adverse human health consequences associated with
chronic low-dose exposure to mercury, public concern has
been seen. For example, in a 1991 survey commissioned by
the American Dental Association, 20 percent of those
responding had considered having their amalgam
restorations removed or had actually had them removed
because of concern over the potential health risks. The
lack of a definitive educational initiative by Federal
health agencies may be a contributory factor in the
anxiety experienced by the public.
The CCEHRP Subcommittee on Risk Management charged
the Education Work Group to consider whether new
consumer and professional educational efforts were
needed. The Work Group reached the following
conclusions:
| The public and the health care community must be
properly informed about the risks and benefits of
dental amalgam. However, this will be difficult in
view of the diverse nature of the intended audiences
and their varying perceptions of risk. |
| Dentists, physicians and other health
professionals need accurate information about the
risks and benefits of all dental restorative
materials in order to provide patients with the
information necessary to make informed and
intelligent choices in regard to dental restorative
material selection or removal. (At present,
available scientific data do not support the need
for removal of otherwise sound dental amalgam
restorations.) |
| Third party payers should be educated on relevant
topics of tooth conservation techniques and
materials such as sealants and preventive resin and
appropriateness of restoration repair in specific
cases to assure reimbursement. |
| In order for any educational program on dental
restorative materials to be credible, it must be
frank about the uncertainties involved. A program
developed with the involvement of consumers,
manufacturers and dental professionals would likely
have balance as well as credibility, and could be
more easily accepted by all communities. |
| The U.S. Public Health Service is a logical source
for educational campaigns on national health issues,
such as amalgarn. The Food and Drug Administration,
the National Institutes of Health and the Centers
for Disease Control and Prevention have the combined
responsibility for national education about health
matters, as well as the contacts and prestige to
make nationwide educational campaigns successful. |
For a detailed discussion of these recommendations
and their rationale, see the Education Work Group report
(Appendix V).
Regulation
Federal regulation of dental amalgam and elemental
mercury as an amalgam component resides with the Food
and Drug Administration. Both products are regulated
under the mandate of the Medical Device Amendments of
1976 and the Safe Medical Devices Amendments of 1990.
The basic framework of these device laws is a
three-tiered regulatory scheme, which classifies devices
on the basis of health risk and sets corresponding
levels of regulatory controls.
Historically, FDA has regulated dental mercury and
amalgam alloys separately, with mercury treated as a
class I device and the alloy as a class II device.
(Medical devices are assigned to class I, II, or III,
depending on the degree of regulatory control needed to
assure the safety and effectiveness of the device, with
class I requiring the least degree of regulatory control
and class III the greatest. Mercury was placed in class
I because, as an element, it could be regulated by
establishing a standard of purity. The alloy was
assigned to class II because of the potential safety and
effectiveness risk that could result from variations in
chemical formulation in terms of percent composition and
types of materials.)
The FDA Dental Products Panel, convened in March
1991, unanimously agreed that sufficient scientific data
do not presently exist to establish dental amalgam as a
human health hazard. The Panel also noted that although
the evidence was anecdotal and inconclusive in
establishing that persons with amalgam restorations
develop any toxic reactions, this potential had not been
adequately studied and warranted further investigation.
This conclusion is consistent with the PHS evaluation of
amalgam risks attached to this report.
For this reason, a Regulatory Work Group (operating
under the auspices of the Subcommittee on Risk
Management) believes FDA should administratively combine
dental mercury and amalgam alloys into a single product
for regulatory purposes. This would enable dental
amalgam, with the mercury component, to be regulated at
the higher, class II level. Based on the absence of
scientific data establishing a causal link between
amalgam restorations and any health problems, class II
provides satisfactory regulatory control of dental
amalgam at this time.
There are two other steps the FDA should consider to
assist dental practitioners to better manage their
patients and to induce providers of dental care to
report adverse reactions to both dental amalgam and
other restorative materials.
| First, FDA should require restorative material
manufacturers to identify the ingredients used in
their products. Industry disclosure of product
ingredients would provide dentists with useful
information with which to diagnose the cause of
sensitivity reactions, and would facilitate their
selection of a substitute material. It should be
noted that the U.S. Occupational Safety and Health
Administration requires dentists, by regulation, to
inform their employees of the hazards involved with
exposure to dental materials. These hazards are
quantified by way of "material safety data
sheets" (MSDS); however, this information does
not specify the exact components of the materials.
Thus, the proposal to have FDA require product
ingredient labeling would ensure full disclosure of
their components directly to practitioners and their
patients. |
| Second, FDA should develop an educational program
for dental providers regarding adverse reaction
reporting. FDA presently operates an adverse
reporting program that serves as a conduit through
which reports on actual performance of medical
devices in the clinical realm can be shared with the
agency. This "early warning" system
enables FDA to pinpoint potentially defective
devices, to alert product uses of a health threat,
and to compel corrective action. It is essential
that FDA initiate appropriate promotional and
educational efforts to foster increased
participation in this program by dentists and their
patients. |
| As part of the review of amalgam use, efforts were
made to ascertain whether dental provides are making
bogus claims that dental amalgam is toxic or a
causative agent for disease and, at the same time,
promoting the replacement of amalgam with other
restorative materials. It is not clear to what
extent this practice may be occurring. In individual
cases of such practice, especially where literature
purporting these claims is made available to
patients, the FDA could take legal action. However,
because this conduct relates to professional ethics,
it seems more appropriate for State licensing
authorities or professional organizations to take
corrective action. False advertising by dental
product manufacturers lies within the purview of
FDA, and thus that agency should closely monitor
promotional materials associated with all dental
restorative materials to ensure that providers and
patients receive accurate information. |
For a fuller discussion of the above issues, see the
Regulatory Work Group report (Appendix VI).
Recommended PHS
Strategy
Research
| Develop a research agenda that considers the Risk
and Benefits Subcommittees' comprehensive review of
the scientific literature, and the list of
scientific questions and research areas identified
by the Research Work Group. In setting out a
targeted research agenda, a comparison should be
made between the existing inventory of research
studies—and the important gaps in current
knowledge about the possible effects of dental
amalgam and non-amalgam alternative materials on the
body. |
Lead agency: NIH, jointly with CDC and FDA Lead
agency: NIH, jointly with CDC and FDA
| To monitor progress in this area, establish a
tracking mechanism to continually identify and
evaluate amalgam research studies funded by the PHS,
as well as those sponsored by other government
agencies and the private sector. |
Lead agency: OASH Lead agency: OASH
Education
Develop a public and professional educational
campaign to explain to dental personnel and consumers
what is and is not known about the safety of dental
amalgam. In order to be credible, the program must
address both the benefits of amalgam and the controversy
that exists regarding the possible biological effects.
Lead agency: CDC, jointly with FDA and NIH Lead
agency: CDC, jointly with FDA and NIH
| Encourage changes in dental restorative practices
such that preservation of sound tooth structure is
maximized, and amalgam and alternative materials are
used appropriately in specific cases. |
Lead agency: NIH/NIDR Lead agency: NIH/NIDR
Regulation
| Combine elemental mercury and dental alloy, which
are presently regulated separately, into a single
product for regulatory purposes. In light of the
studies now ongoing and those proposed in this
report, and given the capacity of the U.S. Public
Health Service to conduct meaningful research in
this area, reclassification of dental amalgam to
class III is premature from the standpoint of public
health and could result in the loss of this material
as a viable treatment option. |
Lead agency: FDA Lead agency: FDA
| Require that manufacturers of all dental
restorative materials, including dental amalgam,
label their products with the ingredients to help
dentists identify patients who may exhibit allergic
hypersensitivity to these substances and select the
appropriate restorative material. |
Lead agency: FDA Lead agency: FDA
| Through educational and promotional efforts,
encourage dentists and patients to report adverse
effects from all restorative materials, including
dental amalgam, to FDA. |
Lead agency: FDA, jointly with CDC and NIH Lead
agency: FDA, jointly with CDC and NIH
Contributors to
the Report
As with any project, there are persons who exert
leadership, offer expert advice and provide technical
support. The preparation of this report, which presents
a strategic plan on dental amalgam safety for the U.S.
Public Health Service, is no exception. Many
individuals, with diverse backgrounds and expertise,
contributed significantly to the preparation of this
report and the deliberations that underlie it.
The report is based on extensive work performed by
two groups: the Subcommittee on Risk Assessment, chaired
by Dr. Vernon Houk, Director of the National Center for
Environmental Health and Injury Control, CDC; and the Ad
Hoc Subcommittee on the Benefits of Dental Amalgam,
chaired by Dr. Harald Loe, Director of the National
Institute of Dental Research, NIH.
Several members of FDA's Center for Devices and
Radiological Health were actively involved in preparing
the present report. Chief among them was Dr. Elizabeth
Jacobson, who provided management oversight of the
project and general direction for the support team that
performed the various tasks. Mr. Robert Eccleston and
Dr. Lireka Joseph served as project coordinators, which
involved project planning, task execution and authorship
of parts of the report
Dr. Stanford Hamburger, Mr. James Morrison and Dr.
Carolyn Tylenda chaired interagency work groups assigned
to analyze the research, education and regulatory issues
respectively associated with dental amalgam and to
recommend actions to define and manage amalgam risks.
Mr. Mark Bamett and Ms. Marcia Meyer also contributed to
the writing of the report. Finally, Mr. Ronald Jans
provided the computer support for generation of the
report and the supporting graphics and other visuals.
Committee
to Coordinate Environmental Health and Related Programs
| Subcommittee on Risk Management James S. Benson,
Chairman |
| Subcommittee on Research Needs Kenneth A. Olden,
Ph.D., Chairman |
| Subcommittee on Risk Assessment Vernon N. Houk,
M.D., Chairman |
| Subcommittee on Risk Communication and Education
Barry L. Johnson, Ph.D., Chairman |
| Ad Hoc Subcommittee on the Benefits of Dental
Amalgam Harald Loe, D.D.S., Chairman |
Interagency Work
Groups
Regulatory Work Group
| Carolyn A. Tylenda, D.M.D., Ph.D. Chair Center for
Devices and Radiological Health, FDA |
| Betty W. Collins Center for Devices and
Radiological Health, FDA |
| W. Don Galloway, Ph.D. Center for Devices and
Radiological Health, FDA |
| Carol M. Lee Center for Devices and Radiological
Health, FDA |
| Charles Somerville Center for Devices and
Radiological Health, FDA |
Education Work Group
| James L. Morrison, M.S. Chair Center for Devices
and Radiological Health, FDA |
| Lawrence J. Furman, D.D.S. Office of the Chief
Dental Officer, U.S. Public Health Service |
| Lireka P. Joseph, Dr. P.H. Center for Devices and
Radiological Health, FDA |
| William G. Kohn, D.D.S. National Institute of
Dental Research, NIH |
| Max Lum, Ed.D. Agency for Toxic Substances and
Disease Registry |
| D. Gregory Singleton, D.D.S. Center for Devices
and Radiological Health, FDA |
Research Work Group
| Stanford E. Hamburger, D.D.S. Chair Center for
Devices and Radiological Health, FDA |
| Thomas J. Callahan, Ph.D. Center for Devices and
Radiological Health, FDA |
| Stephen B. Corbin, D.D.S. National Center for
Prevention Services, CDC |
| Jeffrey S. Gift, Ph.D. Environmental Criteria and
Assessment Office, EPA |
| Peggy M. Hamilton Center for Devices and
Radiological Health, FDA |
| Annie M. Jarabek Environmental Criteria and
Assessment Office, EPA |
| Mark McClanahan, Ph.D. National Center for
Environmental Health and Injury Control, CDC |
| Kevin Tonat, M.P.H. National Institute of
Environmental Health Sciences, NIH |
Food and Drug
Administration
FDA CCEHRP Steering Committee
| James S. Benson, Chairman Center for Devices and
Radiological Health |
| William T. Allaben, Ph.D. National Center for
Toxicological Research |
| Joseph S. Arcarese, M.S. Center for Devices and
Radiological Health |
| Catherine W. Carnevale, D.V.M. Center for Food
Safety and Applied Nutrition |
| Joy A. Cavagnaro, Ph.D. Center for Biologics
Evaluation and Research |
| Joseph F. Contrera, Ph.D. Center for Drug
Evaluation and Research |
| Robert J. Scheuplein, Ph.D. Center for Food Safety
and Applied Nutrition |
| Leonard N. Schechtman, Ph.D. Center for Veterinary
Medicine |
| Angelo Turturro, Ph.D. National Center for
Toxicological Research |
| Ronald F. Coene National Center for Toxicological
Research |
Other Government Reviewers
| Louis F. Cannavale, D.D.S. Indian Health Service |
| Harlal Choudbury, D.V.D.,Ph.D., DABT Office of
Research and Development, EPA |
| Stan C. Freni, M.D., Ph.D., Dr.P.H. National
Center for Toxicological Research, FDA |
| David W. Gaylor, Ph.D. National Center for
Toxicological Research, FDA |
| David L. Greenman, Ph.D. National Center for
Toxicological Research, FDA |
| Louis H. Hlavinka Center for Devices and
Radiological Health, FDA |
| Everett R. Rhoades, M.D. Assistant Surgeon General
and Director Indian Health Service |
Non-Government Peer Reviewers
| Thomas Clarkson, Ph.D. Professor and Director
Environmental Health Science Center School of
Medicine University of Rochester |
| Robert H. Gray, Ph.D. Assistant Dean for
Curriculum and Professor Department of Environmental
and Industrial Health School of Public Health
University of Michigan |
| Paul Goldhaber, D.D.S. Dean Emeritus and Professor
of Periodontology Periodontal Research Center
Harvard School of Dental Medicine |
| Rolf Hartung, Ph.D., DABT Professor of
Environmental Toxicology Department of Environmental
and Industrial Health School of Public Health
University of Michigan |
| J. Rodway Mackert, Jr., D.M.D., Ph.D. Professor
Department of Dental Materials Medical College of
Georgia |
| Irwin D. Mandel, D.D.S. Associate Dean of Research
School of Dental and Oral Surgery Columbia
University |
| John W. Reinhardt, D.D.S. Chairman Department of
Operative Dentistry College of Dentistry University
of Iowa |
| Patricia M. Rodier, Ph.D. Senior Scientist
Department of Obstetrics and Gynecology School of
Medicine and Dentistry University of Rochester
Medical Center |
| Petr Skrabanek, M.D. Professor Department of
Community Health Trinity College - Dublin, Ireland |
| James S. Woods, Ph.D., DABT Senior Research
Scientist Batelle Seattle Research Center |
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Dental
Information
