This dental materials "fact sheet" was presented for consideration at the July 10, 2003 meeting of the Dental Board of California. It was prepared by a committee chaired by board member Chester Yokoyama, D.D.S., a long-time opponent of amalgam fillings. It was supposedly intended to be a "more consumer friendly" addition to the board's current fact sheet. However, there is no evidence that the current fact sheet is inaccurate or is not consumer-friendly. Distributed in 2002, it reflects the current regulatory and scientific consensus that amalgam is safe and is commonly the best material for fillings in posterior teeth (molars and premolars), based on cost, durability, strength, and ease of placement. After the current fact sheet was prepared, amalgam opponents persuaded the state legislature to shut down the board so that Governor Gray Davis could appoint new members who were anti-amalgam. The board has sent Yokoyama's document to the Consumer Affairs Agency for review and plans -- at its next meeting -- to consider adopting it as a substitute. Here is our line-by-line analysis.
Dentists throughout California and the Dental Board of California are concerned about the health of patients and the safety of dental treatment. The Dental Board of California has prepared this consumer-friendly version of the dental materials fact sheet to help you understand the advantages and the disadvantages of the most common dental filling materials. [This new compilation of information is not consumer friendly. It is filled with false and misleading statements, and its overall tone will create unnecessary fear and confusion.] This information is being supplied to encourage you to discuss with your dentist, the benefits and the risks that these filling materials have on your dental and general health. [Competent and ethical practitioners do not need a government mandate to discuss the pros and cons of various types of fillings. That is part of appropriate standard care. This fact sheet, quite simply, is part of a political effort by a small minority of dentists whose opinions are not based on science or data to impose their beliefs on the rest of the profession.] All the materials in this fact sheet have been studied by the U.S. Food and Drug Administration and have been approved for use for the general population. [An honest fact sheet would say that the FDA's approval was based on sound scientific knowledge and indicates that all of the materials are safe.]
Some of the filling materials contain metals and chemicals that could affect a patient, most often an allergic reaction in certain individuals. Toxic reactions to filling materials are thought to be rare. [They are not merely "thought to be rare." They do not exist. No credible reports of toxic reactions to any kind of filling material have ever been published.]
1. Dental amalgam fillings give off mercury. Mercury vapor can be inhaled and enter the body but the amount is thought to fall below safe limits set for exposure. [It is not merely "thought" to be safe. The amount inhaled is known to be extremely small and far below toxic levels. More important, the statement lacks perspective. An honest statement would compare the amount the body gets from amalgam with accepted limits and the amounts that people get from other sources.] There are different opinions about the risk of mercury in dental amalgam fillings, including the potential for risk in pregnant women and young children. [This falsely implies that the opinions of a few amalgam critics are somehow equivalent to those of public health experts and other segments of the scientific community. The phrase "potential risk" is misleading. There is no known risk.] In March 2003, organized dentistry issued the following warning as part of a notice to patients:
PROPOSITION 65 WARNING: Dental Amalgam . . . causes exposure to mercury, a chemical known to the State of California to cause birth defects or other reproductive harm. [The "warning" was not issued by "organized dentistry." It was released by the California Dental Association as part of the settlement of a lawsuit about the notice required by Proposition 65, a law that is way out of step with scientific reality. It applies only to members of the association whose offices have 10 or more employees.] Although the passage might suggest danger, it neither says nor means that amalgam causes cancer or reproductive harm. Moreover, the quoted sentence is only part of the notice, which goes on to say: "The US Food and Drug Administration has studied the situation and approved all dental restorative materials for use." Using one sentence out of context is evidence of dishonesty.
A message to parents and pregnant women: Because mercury can harm the developing brain, of a child or fetus, an intense debate exists about the risks of dental amalgam for children and pregnant women. There is a difference of opinion on the scientific studies proving mercury from dental amalgam fillings is safe or unsafe. [A few people believe that drilling a hole in the skull is mentally uplifting. The rest of the world thinks otherwise. Would it be proper to characterize this as an "intense debate"? There is no difference of opinion among credible scientists that amalgam is safe and effective for its intended use.]
2. Some crowns and bridges contain a nickel-chromium-beryllium alloy. Nickel and beryllium, like mercury are toxic metals. Approximately 10% of females have an allergy to nickel. [Whether something is toxic depends on the dose. Except for allergies, which are uncommon, no patients has ever been harmed by the nickel or beryllium contained in alloys.]
3. Composite filling material contains some compounds listed on the Prop 65 List but health concerns have not been supported by scientific evidence. [Scientific evidence does not support the idea that any dental restorative material poses a health threat. The fact that the antiamalgamists have pressed for Proposition 65 warnings against amalgam but not for composite materials is additional evidence of their dishonesty. ]
Composite is a mixture of powdered glass and plastic resin. These fillings are also called "plastic" or "white" fillings.
Dental amalgams are made of mercury, silver, copper and tin. The major component is mercury, about 40 to 50%. Dental amalgams are often referred to as "silver" fillings, even though there is almost twice as much mercury as silver.
- Dental amalgam is very strong, lasts a long time and is usually done in one visit.
- This is the least expensive type of filling material.
Glass ionomer is a glass product. It is used for small or temporary fillings. It is usually not used on the chewing surfaces of back teeth.
Gold Alloy Fillings
Gold alloy fillings are a mix of gold and other metals such as silver and copper. Fillings made of gold alloy are made in a dental lab and sent back to the dentist to cement into place.
Porcelain is a mix of glass-like materials. Sometimes it is called ceramic. Fillings made of porcelain are made in a dental lab and sent back to the dentist to cement into place.
The durability of any dental restoration is not just influenced by the material it is made from but also by the dentist's technique when placing the restoration, the supporting materials used in the procedure, and the patient's cooperation during the procedure. The length of time a restoration will last is dependent on your dental hygiene, home care, diet and chewing habits.