Home FDA Shocking Decision Bias Seen in Dental Amalgam Rule


[Analysis by Jim Dickinson,* www.FDAweb.com]
Although FDA estimates there were 154 million teeth filled last year
with mercury-laced dental amalgams, this is a small and fast-shrinking
market that’s yielding to safer alternatives. Which makes it all the
harder to understand why FDA 7/28 capped a flawed, 32-year effort to
support the use of this notorious environmental toxin in dentistry by
announcing a final rule classifying it as a Class II medical device.
Rule making is supposed to be an objective process, and all the more
so when it is scientific rulemaking. Egregiously, this one was not.

FDA’s announcement was “shocking,” declared the Florida-based
International Academy of Oral Medicine and Toxicology in a press
release. “Dental amalgam is universally acknowledged to expose people
to mercury, but by declaring it a Class II device the FDA has passed
on the opportunity to require proof of safety from its manufacturers.
Instead, FDA has declared it safe by administrative fiat.”

Unlike most controversial FDA decisions, that administrative fiat has
little to no backing from a powerful regulated industry whose ox might
otherwise have been gored in a stronger rulemaking. In fact, one
industry analyst, Northcoast Research, told its clients that far from
protecting mercury’s market share, the rule might actually expedite a
shift to costlier, less durable and more profitable composite resin
alternatives — clearly not what the FDA rulemakers intended.

Buried in the depth of the preamble to the rule, on Page 86 of its
typescript, under the heading, “Risk,” the intent and the bias of its
principle author — thought to be dentist Susan Runner, acting director
of CDRH’s Division of Anesthesiology, General Hospital, Infection
Control, and Dental Devices — can be discerned: to promote public
health through more, not less use of mercury amalgams.

“[A]ny change away from use of dental amalgam,” the preamble baldly
says, “is likely to result in negative public health outcomes (delayed
dental treatments or increased costs of treatment); while there would
be a decrease in mercury exposure, there is no evidence that there
would be any reduction in adverse affects associated with mercury.
Conversely, any change toward use of dental amalgam is likely to
result in positive public health outcomes (fewer delayed dental
treatments or decreased costs of treatment).”

This statement is repeated word-for-word on Page 96, under the heading
“Potential Public Health Effects of the Final Rule.”

In a particularly obtuse and speculative section, “Alternatives to the
Final Rule,” FDA presents no factual reference whatever, but projects
an unsubstantiated theoretical cost to the country of $63.9 million in
delayed treatments and higher costs if dental amalgam is no longer
available and dentists are forced to use more expensive and less
durable alternative materials.

The preamble appends 88 references reflecting biased selections of
literature that almost invariably reference studies vaguely
exonerating dental mercury from human harms, even while repeatedly
acknowledging “gaps” in human data and falling back on animal studies
and epidemiologic meta-analyses instead. FDA Webview could find no
anti-amalgam study conclusions in the one-sided literature that FDA

However, in a 15-minute Google search, FDA Webview found four such
studies that were not included in FDA’s bibliography (but doubtless
Runner could find them not in compliance with the regulatory
definition of “valid scientific evidence” notwithstanding that many of
her own 88 references in the preamble also appear to have that
deficiency, including a discredited 2006 FDA White Paper declaring
dental amalgams safe and a controversial mercury-exonerating study
done for FDA by the Beltway consulting firm LSRO cited favorably in
the preamble): A high proportion (mean 77% SD 17%) of inorganic
mercury was found. It is concluded that the cause of the association
between amalgam load and accumulation of mercury in tissues is the
release of mercury vapor from amalgam fillings. Nylander, M. et al,
Swedish Dental Journal (1987)

The results showed that examined subjects with dental amalgams had
higher pre-chewing mercury levels in their expired air than those
without amalgams. After chewing, these levels were increased an
average of 15.6-foldin the former and remained unchanged in the latter
group. It was concluded that in situ dental amalgams can increase the
level of mercury in expired air. Svare et al, Journal of Dental
Research (1981)

Blood mercury concentrations were positively correlated with the
number and surface area of amalgam restorations and were significantly
lower in the group without dental amalgams Abraham et al, Journal of
Dental Research (1984)

The report points out, supported again by a multitude of studies, that
amalgam contributes more mercury to the human organism than all other
sources from the environment (food, water, air) combined. Kieler
Amalgam Gutachen (2002 German Govt. study) Among the preamble’s 88
references, however, were two ambiguously described votes from a 2006
joint meeting of FDA’s Dental Products Panel and Peripheral and
Central Nervous Drugs Advisory Committee on amalgam. As reported at
the time, but not in FDA’s final rule preamble, these declared by 13-7
majorities that FDA’s White Paper did not objectively and clearly
present the current state of knowledge about them, and that the White
Paper’s conclusions about safety were not reasonable.

In July, before it announced the final rule, which is to publish in
the 8/4 Federal Register, FDA updated the White Paper in response to
those criticisms, but its updates were largely technical, not
substantive. Simultaneously, it updated CDRH’s amalgams Web page to
remove advisory language saying: “Dental amalgams contain mercury,
which may have neurotoxic effects on the nervous systems of developing
children and fetuses.” FDA is about to be sued in federal court over
this, according to Consumers for Dental Choice national counsel
Charles G. Brown.

Among its responses to some 3,000 public comments on the proposed
rule, published in 2002, the final rule’s preamble conceded that
mercury does cross the placental barrier but cited a lack of human
data on fetal effects. The preamble acknowledged one animal study that
showed no fetal effects and another showing “adverse effects on fetal
development only in cases where maternal exposure to mercury vapor was
so high that it became toxic to the mother (leading to decreased
maternal body weight).”

There were two substantive White Paper updates among the eight FDA
listed in its preamble to the final rule: (1) The label warning about
zinc in amalgam was changed to a warning about the presence of
mercury; and (2) Submitters of 510(k)s for mercury amalgams were
required to include test data about the amount of mercury vapor
released by their device.

Dental product labels, however, are seldom read by patients.

As it typically does in preambles to final rules, FDA’s discussion of
these 3,000 comments did not break them down into for-and-against
counts, nor did it provide per-topic counts; instead it used, as it
typically does, vague adjectives like “many” when more than several
commenters made the same point.

Accordingly, the agency admitted that “many” commenters wanted amalgam
classified into Class III, an effective ban. But, since rulemaking is
not a popularity contest or a ballot, the agency overruled these
commenters, citing regulatory alibis, rather than substance.

“In reaching this determination,” it wrote, “FDA made the findings
required by § 860.7(d)(1) that, first, when subject to the general
controls of the act and the designated special control, and when
accompanied by warnings against unsafe use in individuals who are
allergic to mercury, the probable benefits to health from use of the
device outweigh any probable risks. Second, FDA has determined that,
when subject to the general controls of the act and the designated
special control, valid scientific evidence demonstrates the absence of
unreasonable risk of illness or injury associated with the use of the
device for its intended uses and conditions of use.”

In response to comments asking FDA to ban mercury amalgams as other
countries have done, the agency’s biased preamble said it “recognizes
that certain countries, e.g., Norway, Sweden, and Denmark, have banned
dental amalgam, adopting a ‘precautionary principle’ approach (taking
preventive action despite uncertainty regarding the need for such
action). However, FDA regulates devices, like dental amalgam, in
accordance with the requirements of the act. As explained above, in
accordance with the statutory criteria for classifying devices, FDA
has concluded that there is sufficient information from which to
establish special controls that, along with the general controls of
the act, will provide reasonable assurance of the safety and
effectiveness of the device.”

FDA also showed its bias in a response to two comments requesting
disclosure of mercury in amalgam labeling “citing to a recent poll
showing that 76% of Americans do not know that the primary component
of amalgam fillings is mercury,” and disclosure of the amount of
mercury vapor released. Clearly, the implication of these comments was
that patients should be told. Yet in its response, FDA said it agreed
that “dental professionals” should be alerted in the device labeling,
but said nothing about also alerting patients.

Directly addressing other comments asking for patient informed consent
before mercury amalgams are inserted, the preamble said that because
dental decision-making is a “complex matter” when selecting
restorative materials to use for fillings, “FDA has concluded that it
is not necessary to require that dentists provide this information to
patients in order to provide reasonable assurance of the safety and
effectiveness of the device.” Patient involvement in such decision-
making was not addressed here.

Several comments directly accused FDA of being biased in favor of
mercury amalgams through being, the preamble characterized, “too
closely aligned with the interests of professional dental
organizations and, as a result, has unfairly discounted evidence
regarding the health risks presented by dental amalgam.”

Unable to document the agency’s deliberative open-mindedness, the
preamble retorted: “FDA disagrees with the comments suggesting that it
has been biased in its approach to regulating these devices. This
final rule and the special controls guidance document reflect FDA’s
careful and impartial consideration of all the comments and
information it has received, the scientific information and safety
assessments discussed previously, the White Paper and Addendum
reports, and the adverse event reports submitted regarding these

“FDA has been proactive in obtaining as much information as
practicable regarding the safety of these devices. As described
previously, FDA has undertaken or supported several safety assessments
since the early 1990s regarding dental amalgam. In 2006, in an effort
to ensure a transparent, public forum for discussion, FDA convened a
joint committee of panelists with diverse backgrounds, including
neurology and toxicology experts, to consider FDA's most recent review
of the scientific literature related to dental amalgam (the White
Paper) as well as presentations from members of the public.”

FDA can be proactive and transparent in obtaining information from the
public, but this rule demonstrates that what it subsequently does with
that information can be far from proactive and transparent.

As one apparently knowledgeable FDA employee commented to our report
on the rule’s announcement: “Why continue to use and recommend mercury
amalgam when there is safer composite alternative? No dentist in our
area will use mercury because it is considered a hazardous waste and
expensive to deal with. Composite is the only option, but insurance
will only cover them for the same amount as mercury, with the patient
responsible for the difference. I really question FDA's motivation
here. It seems to be more responsive to industry than human health.”

FDA is congenitally unable to respond to such comments, nor does it
see a need to do so. Commissioner Margaret Hamburg, who has recused
herself from this matter because of a possible conflict of interest
issue arising from her prior employment, has in a recent presentation
emphasized the great importance of improving FDA’s regulatory science.

Her necessary absence from this rulemaking is to be regretted, because
its inability to demonstrate even C-grade regulatory science, much
less improved or “new” regulatory science, is all too apparent here.

Through its biased accumulation and assertion of evidentiary resources
and its apparent escape from rigorous internal process validation and
scientific challenge, this is the most flawed example of FDA
rulemaking I have witnessed in 33 years of reporting this once-great

* Jim Dickinson is editor of FDA Webview.

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