Legislation and Informed Consent Brochures for Dental Patients Receiving Amalgam Restorations

Abstract

In 2008, Norway banned the use of mercury for amalgam restorations. Four states in the United States have developed Informed Consent Brochures for amalgam restorations that must be given to their dental patients. The authors describe a patient who had a large cavity in his left lower molar tooth no. 18 that had to be removed by an oral surgeon. When the patient went to the oral surgeon, the surgeon told the patient that he would replace the carious tooth with a gold implant. He was not given an Informed Consent Brochure regarding dental restorative materials. The oral surgeon extracted the carious tooth, replacing the tooth with a supposed gold crown implant. On his yearly dental examination, his dentist took an x-ray of his dental implant and explained that the x-ray could not distinguish whether the implant contained either gold or mercury. Consequently, the dentist referred him to a dental clinic in which the dental implant could be removed without mercury contamination of the patient’s neurologic system during the extraction of the implant from the root canal. During the removal of the dental restoration, the dentist found build up expanding into the root canal that had a black color. The crown and underlying tooth were sent to ALT BioScience for analysis. Elemental analysis of the crown and underlying tooth confirmed the presence of mercury in the restoration. The patient should have been given an Informed Consent Brochure by the dentist that described the dental restoration that was used in the dental implant.

Mercury-containing amalgam dental restorative materials have been the most widely used dental restorative materials in the last 150 years (Mitchell, Osborne, and Haubenreich 2005; Soler et al. 2002; Eley 1997). Mercury amalgam has been used in more patients than any other dental restorative material. Between the middle and end of the 19th century, the mercury alloys were changed to contain 20 to 30 wt. % tin and lesser amounts of copper and zinc were gradually developed. These changes in formulation were begun slowly by trial and error and later by systematic studies (Escheverria et al. 1998). The general formulation for amalgam did not change for the next 60 years (Eley 1997). During the 1960s, larger amounts of copper in the alloy powder, between 13 and 30 wt. %, were shown to eliminate a weak and corrosion prone Sn-Hg phase and to enhance the resistance of tooth-restoration interfaces to tooth fracture (marginal fracture) (Mahler 1997). Today, the Hg content of most Hg composites is 50% of the composite.

The purposes of this article are the following: (1) to review the systemic and local pathologic effects of mercury amalgam restorations; (2) to discuss the institution of legislation as well as patient consent brochures for patients receiving dental restorations in four states in the United States; and (3) to describe a case report of a multiple sclerosis patient who received a mercury implant beneath a gold crown without his permission.

MERCURY TOXICITY

The discovery that amalgam releases mercury during chewing has led to concerns about the safety of this restorative material. It has been well documented that mercury amalgam continually emits mercury vapor, which is dramatically increased by chewing, eating, brushing, and drinking hot liquids. Mercury has been demonstrated to have damaging, nonspecific psychological and somatic effects (Weiner, Nylander, and Berglund 1990; Escheverria et al. 1998) as well as specific pathologic effects on the kidney (Mortada et al. 2002) and the central nervous system (multiple sclerosis [Huggins and Levy 1998; Bangsi et al. 1998], autism [Needleman2006; Bellinger et al. 2006; DeRouen et al. 2006; Holmes, Blaxill, and Haley 2003; Nataf et al. 2006; Takahashi et al. 2000], Alzheimer’s disease [Saxe et al. 1999; Ely 2001; Schipper HM 2004]) and has been implicated in adverse effects on the cardiovascular system (Siblerud 1990; Issa et al. 2005; Lau et al. 2001). It must be emphasized that this amalgam also results in a mucosal tattoo adjacent to the restorative material (Shah and Alster 2002; Ritchie et al. 2004).

LEGISLATION AND INFORMED CONSENT BROCHURES FOR AMALGAM COMPOSITES USED IN DENTAL PATIENTS

Realizing the environmental dangers of mercury, the Norwegian Minister of the Environment and International Development, Eric Solheim, has prohibited the use of mercury in products in Norway (Solheim 2007). This ban includes dental filling materials (amalgam’s) and measuring instruments, as well as other products. This ban has been valid since January 1, 2008. Sweden announced a similar ban and dentists in Denmark are no longer able to use mercury in fillings after April 1, 2008 (Edlich et al. 2008).

“These bans clearly indicate that amalgam is no longer needed. There are viable non-mercury filling substitutes that are used every day in the U.S.” said Michael Bender director of the Mercury Policy project (Edlich et al. 2008). Since the health insurance stopped paying for amalgam restorations in Sweden in 1999, the use of mercury amalgam restorations has decreased markedly and is now estimated to be only 2% to 5% of all fillings.

Individual state legislatures are beginning to understand that mercury from amalgam restorative material may contribute to health problems and are enacting informed consent legislations. In 2001, the Maine State Legislature passed a Law telling the Maine Bureau of Health to make a brochure about the advantages and disadvantages to human health and the environment of using mercury amalgam restorations in dental work. The Law mandates that every dentist’s office will feature a poster and a brochure informing patients about the presence of mercury in amalgam restorative material and about its negative health effects. This brochure is available to the reader online at http://www.maine.gov/dhhs/index.shtml. In this brochure, the Maine Board of Health points out that some people have allergic reactions to mercury and that too much mercury can damage the kidney, nerves, and the brain. The brain of babies and infants that are starting to form and grow are most at risk. It points out that Canada and several countries in Europe recommend limits on the use of mercury amalgam restorations. These countries advise that pregnant women should not have amalgam restorations placed in or removed from their teeth. Some of these countries have the same warning for nursing women and people with kidney problems. Some of these countries advise limits on using mercury amalgam restorations with young children and people with braces. This brochure further emphasizes that the U.S. Public Health Service does not think that the above health care advice is needed.

The Maine Bureau of Health also indicate that some other countries limit the use of amalgam fillings to help reduce mercury pollution. It points out that waste is made when new fillings are put in teeth or when fillings are removed. In an effort to reduce the environmental pollution of mercury, your dentist can reduce the pollution by using traps and filters to collect the mercury for recycling. Mercury amalgam restorations release mercury into the human digestive system (urine and feces) that ultimately become part of the sewage that will add to the pollution of the ocean. Many states, including Maine, have included Safe Eating Guidelines on eating fish due to mercury pollution It is important to emphasize that mercury used in dentistry is not the major source of mercury pollution that results in fish safety warnings. In 1992, the Dental Board of California also enacted legislation that required dentists to give a brochure to their patients who will be getting dental restorative material. The brochure was completed in May 2004. Copies of this brochure can be obtained online at www.dbc.ca.gov.

In 2002, the Connecticut State Legislature passed a Law requiring the Connecticut Department of Environmental Protection to develop the best management practices for the handling of dental amalgam. In January 2006, the State of Connecticut Department of Environmental Protection created a brochure on dental restorations. This brochure is available online at www.ct.gov/dep. The reader will note that the brochure is very similar to the brochure developed by Maine Department of Human Services Bureau of Health. You will note that the picture on the cover of the brochure is identical to the picture in the Maine Brochure on dental restorations. This brochure is required to be given to every dental patients who receive dental restorations. In this brochure, there is a discussion about the health effects of mercury as well as its environmental effects to the constituents of Connecticut. It also points out again that the U.S Public Health Service thinks this advice is not needed.

The State Government of Vermont passed a Law that requires that a brochure be given to all dental patients receiving restorative dental therapy. This Law has been enacted in 2008.

CASE REPORT

In this 68-year-old patient with multiple sclerosis, the diagnosis was made when he was 46 years old. His diagnosis of weakness in legs was precipitated by the development of hyperthermia in the summer months, making it difficult for him to walk rapidly or run. It is well known that hyperthermia has potentially serious adverse complications in patients with multiple sclerosis, and will elicit a variety of neurologic signs, including muscle weakness (Edlich et al. 2004). His primary care physician referred him to a neurologist who ordered a magnetic resonance imaging (MRI) of the patient’s head as well as an examination of his cerebral spinal fluid. The MRI showed evidence of multiple T2-weighted lesions. In addition, cerebrospinal fluid abnormalities were detected that consisted of mononuclear cell pleocytosis, an elevation in the level of total immunoglobulin (Ig), and the presence of oligoclonal Ig. Examination of venous blood revealed no evidence of human T-cell lymphotropic virus type I (Edlich, Arnette, and Williams 2000).

Two years before the diagnosis of multiple sclerosis was made, the patient received his yearly dental examination. His dentist found a large cavity in his left lower molar tooth no. 18, which had to be removed by an oral and maxillofacial surgeon who was skilled in tooth extraction of infected teeth and replacement of the carious tooth with a dental alloy that extended into the root canal. When the patient went to the oral and maxillofacial surgeon, the surgeon recommended total replacement with a stainless steel post and a gold crown. He did not provide the patient with any written information. However, the patient was comforted by the surgeon who showed a mirror image of his implanted stainless steel post supported gold crown.

During his yearly dental examination, the patient requested that his dentist take an x-ray of his teeth to be sure there were no mercury amalgam restorations. When the dentist examined the root canal of tooth no. 18, he explained to the patient that he could not identify the type of metal implant below the gold crown. The x-ray revealed that the appearance of the gold crown and metal post and build up were very similar (Figure 1). Consequently, the patient identified a dentist who follows the comprehensive guidelines outlined by Dr. Hal Huggins that protects the patient from mercury contamination of his/her neurologic system during the extraction of the tooth from the root canal (Huggins and Levy 1998). The dental operatories were equipped with negative-ion generators, charcoal air filters, and high-suction evacuation capability. Intravenous vitamin C was administered (50 mg) before, during, and after the dental procedure. Much to the patient’s surprise, build up expanding into the root was composed of mercury (Figure 2a to 2c). The detection of mercury in the implant was done by Dr. Boyd Haley, Department of Chemistry, University of Kentucky (Lexington, KY), using a Nippon mercury vapor analyzer. The implant sample was incubated in distilled water for 2 h and aliquots of this water showed evidence of mercury.

All of the ossicular ligaments in the root canal were removed using an oscillating metal sanding device. After blood was evacuated from the canal, the mucosa was approximated with a 4/0 synthetic absorbable suture. A temporary bridge compression plate was used to cover the healing mucosa, which allowed a permanent fixed partial denture to be manufactured for placement at the site of the removed mercury composite and gold crown 7 days later.

DISCUSSION OF DENTAL INFORMED CONSENT BROCHURES

As the debate continues about the safety of silver mercury restorative materials, all individuals in a democratic country would agree that the patient should receive informed consent material about dental restorations that will be placed in his/her mouth. Dr. Michael Fleming (2007) has spoken eloquently on the informed consent process for patients receiving dental restorations:

“The burden to obtain the necessary information to make informed treatment choices does not rest solely on the patient. It is the dentist’s legal duty to inform patients of the known risks and benefits of proposed treatments, including restorative procedures. Providing answers only when patients ask about amalgam or any other material is only part of the informed consent process. The greater challenge before the profession is establishing what needs to be said when patients do not ask. Silence is a poor option given the current litigious environment and the persistent doubts about amalgam safety. Dentists do not need to place themselves in the position where their patients have little or no idea what was installed in their mouths. Patients do not necessarily need or want to know everything, but they can know more than what they are typically told—that they just got a root canal, a filling, or a crown. When patients ask for information, dentists and staff members cannot afford to respond in a dismissive or condescending manner simply because they are asking hard questions. In this regard, the need to listen carefully and compassionately to patients cannot be overemphasized. Yes, it takes time to answer the questions and participate in active dialogues with patients on matters that concern them. Is it worth it? Absolutely! Patients will admire and respect a dentist for it.”

It is useful to mention that the Informed Consent Brochure will provide the patient assurance about the impending treatment(s) procedures and will allow the patient to learn about the treatment(s) that will be performed on him/her. In addition, it will also provide dentists with a legal document to safeguard their interests in the event of an untoward incident during or after treatment.