Testimony

Statement by
Norris Alderson, 
Director
Office of Science and Health Coordination
FDA

on
Dental Amalgams and the National Environmental Policy Act of 1969 

before
House Subcommittee on Domestic Policy
U.S. House of Representatives

Wednesday, November 14, 2007

Introduction

Mr. Chairman and Members of the Subcommittee, I am Dr. Norris Alderson, Director, Office of Science and Health Coordination at the Food and Drug Administration (FDA or the Agency).   I appreciate your invitation and the opportunity to discuss the issue of dental amalgams and FDA’s implementation of the National Environmental Policy Act of 1969.  

In my testimony today, I will first briefly describe dental amalgam and how FDA regulates these medical devices.   Then, I will describe Federal government activities related to dental amalgam.   I will also describe FDA’s implementation of the National Environmental Policy Act of 1969 with respect to dental amalgam.

Background

Dental amalgam is a restorative material that is used for direct filling of carious lesions or structural defects in teeth.   It is made onsite in a dentist’s office by mixing elemental (liquid) mercury and a powdered (amalgam) alloy composed primarily of silver, tin, and copper (the mixture is also called "encapsulated amalgam alloy and dental mercury" or simply "encapsulated amalgam"). 

Let me begin with a brief overview of our regulatory authorities regarding medical devices and how we exercise them in the case of dental amalgam.   As defined by Federal law, the term “medical device” encompasses several thousand health products, from simple articles such as tongue depressors and heating pads, to cutting-edge and complex devices such as pacemakers, lasers and imaging technologies.   Dental amalgam, as well as its components – dental mercury and the alloy with which the mercury is combined – are medical devices.   The Medical Device Amendments of 1976 to the Federal Food, Drug, and Cosmetic Act (FD&C Act or the Act) gave FDA specific authority to regulate the safety and effectiveness of medical devices.   The FD&C Act prescribes a variety of mechanisms to achieve this goal.  These include classification of medical devices, establishment registration, Quality Systems Requirements for manufacturing, and controls over the market introduction of medical devices.

Classification and Reclassification of Medical Devices

Devices that were in commercial distribution before the enactment of the Medical Device Amendments of 1976 (May 28, 1976), are commonly referred to as “preamendments devices” and were assigned to one of three “classes” consistent with the procedures described in the statute.   Under section 513 of the Act, FDA classifies preamendments devices according to the following steps: (1) FDA receives a recommendation from a device classification panel (an FDA advisory committee); (2) FDA publishes the panel’s recommendation for comment, along with a proposed regulation classifying the device; and (3) FDA publishes a final regulation.   The Act also has a specific procedure for effecting a change to the classification of a preamendments device, which includes issuing a regulation (section 513(e) of the Act) and, if the Agency believes appropriate, obtaining a recommendation from the panel that provided the original classification recommendation.   Devices that were first introduced into commercial distribution after enactment of the Medical Device Amendments Act of 1976, are known as “postamendments devices.”

Let me describe the statutory criteria FDA used when classifying medical devices.   Devices posing the lowest risk, such as elastic bandages, were placed in Class I.   Class I devices are subject to the “general controls” applicable to all devices.   Class II devices, which pose incrementally greater risk and for which general controls are not sufficient to provide reasonable assurance of safety and effectiveness, are subject to “special controls” in addition to general controls.   Special controls may include labeling requirements, performance standards, post-market surveillance studies to conformance with mandatory performance standards, or other controls the Agency deems necessary to provide reasonable assurance of the safety and effectiveness of the device.   The riskiest devices, such as some implants and life-supporting or life-sustaining devices, are placed in Class III and may be marketed only after approval of a premarket approval application, which includes clinical studies and other information establishing the safety and effectiveness of the device.   Preamendments devices classified into Class III are not subject to the requirement of premarket approval until the Agency issues a regulation requiring the submission of applications. 

Dental mercury and amalgam alloy are preamendments devices that FDA classified in accordance with the procedure described above.   In a Final Rule published on August 12, 1987, FDA placed dental mercury into Class I (Title 21, Code of Federal Regulations, section 872.3700) and amalgam alloy into Class II (Title 21, Code of Federal Regulations, section 872.3050).   This action was taken because comments submitted to the Agency acknowledged that the risks to health presented to dentists and other dental workers are inherent in the device and would not be reduced through establishment of performance standards for the device.   The comments also stated that manufacturers have voluntarily accomplished actions to protect dentists and others from the inherent risks presented by the device such as packaging the device in leak proof containers and placing cautionary statements in the labeling of the device.   FDA agreed with the comments urging that dental mercury be classified into Class I.   The encapsulated form of amalgam, which consists of measured proportions of amalgam alloy and dental mercury that are separately sealed and sold as a single-use capsule, was not separately classified during the original classification process.  However, like other products that are a combination of more than one device, FDA has regulated the encapsulated amalgam in accordance with the requirements applicable to the component with the higher classification.   Accordingly, the encapsulated form of amalgam (which includes amalgam alloy and dental mercury) is regulated as a Class II device.

The Dental Products Panel of the Medical Devices Advisory Committee met in 1993 and 1994 to discuss the classification, reclassification and safety of dental amalgam devices.  After considering testimony and other information, the Panel unanimously recommended to classify dental mercury and amalgam alloy intended for the restoration of teeth into Class II.  The Panel also recommended that the device be subject to voluntary performance standards, voluntary testing guidelines, and requirements that the device be used only on the written or oral authorization of a licensed practitioner, and only by persons with training or expertise in its use.   The Panel stated that there were no major risks associated with encapsulated amalgam when used as directed, but recognized there was a small population of patients who may experience allergic reactions to the materials in the device.   The Panel also noted that improper use of the device by practitioners presented risks associated with mercury toxicity.  

As mentioned earlier, the FD&C Act authorizes the Agency to “reclassify” a medical device into a different regulatory class as more knowledge emerges regarding product risk gained from actual use.   In most cases, devices are down-classified.   Occasionally, however, devices are reclassified into a higher class.

2002 Proposed Rule Reclassifying Amalgam Products

In February 2002, FDA proposed a rule to bring all amalgam products into Class II and increase the Agency’s regulatory oversight over these devices by requiring ingredient labeling and proposing conformance to international standards.   By requiring disclosure of amalgam ingredients, the Agency believed the rule would help dental providers to quickly diagnose and treat rare allergic reactions arising from exposure to amalgam components.   Given the high level of interest in this proposed rule, FDA twice reopened the comment period and received more than 750 comments submitted to the docket.

FDA received significant adverse public comments on the 2002 proposed rule.   The majority of the comments stated that the Agency was not proposing enough restrictions on the marketing and use of dental amalgam and that the proposed special controls did not adequately address the potential health risks of the device.