Toxic Conspiracies FAQ.

Or: "I can no longer sit back and allow Communist infiltration, Communist indoctrination, Communist subversion, and the international Communist conspiracy to sap and impurify all of our precious bodily fluids." General Jack D. Ripper, from the 1964 Stanley Kubrick movie Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb

The media is rife with stories about environmental calamity, toxic spills, and corporate cover-ups. Is the dental profession part of the problem or part of the solution?

Q: I want to know the harmful effects of fluoride in a toothpaste, especially for the people who consume fluoride through ground water. Also, I'd like to know if 1000ppm of fluoride in toothpaste can be harmful for kids who happen to eat toothpaste.

A: At about 0.15%, or 1500 ppm, most fluoride toothpastes have a fluoride concentration approximately 2143 times that of fluoridated water (this presupposes an optimal concentration of 0.7 ppm, which is the target level of fluoride in municipal water systems in temperate climates). This can make the issue of whether a person normally drinks fluoridated water statistically insignificant if he eats toothpaste!

The smaller size of a child's body produces a proportionately greater physiologic effect from a drug dose when compared with that in the adult. Consequently, as would be the case for any therapeutic substance or medication administered to a young child, close supervision is in order when he brushes with a fluoride toothpaste. The quantity of toothpaste used should be limited to a very small amount.

Dental fluorosis, or aberrant enamel formation resulting from excessive fluoride intake, manifests as yellow or brown intrinsic staining of the teeth. It will only result if exposure to excessive fluoride occurs before the age of five or six; after that, any significant staining will only occur on the back teeth, if at all.

Keep in mind that public water systems, if fluoridated, will have the fluoride concentrations adjusted to an appropriate level; if you are using "ground water" for drinking as you say, it would be appropriate to test for bacterial and chemical impurities in general, as well as fluoride levels in particular.

Q: I would like to know what type or types of dental crown to choose from that would not have toxic metals in it. I want to avoid the heavy metals that are known to cause ill health in individuals i.e. silver, tin, cadmium etc. Can you assist me with pertinent information?

A: The American Dental Association Council on Dental Materials and Devices formulates standards for materials used in the mouth, and evaluates new materials for both safety and effectiveness. In the case of metals used in crowns, they have been know to mis-step: for example, in the mid '70's some ceramic alloys were permitted to contain nickel, a known allergen. Other than that, they subject materials to scrupulous tests for bio-compatibility. Although all members of a profession must keep in step with additional information as it becomes available, the dental materials currently in use in the United States are generally thought to be both safe and effective. To assume that the profession has not taken toxicologic factors into account is an insult to its members. By the way, the toxicological properties of dental materials should not be the subject of "strong feelings", as may be the case in politics and religion; it should be the subject of scientific inquiry, not conjecture, opinion, or anecdotal observation.

Q: Is the amount of radiation given during an x-ray harmful, and exactly how much radiation is exposed.

A: The amount of x-radiation that is absorbed by a patient is generally not thought to be harmful, although good radiation hygiene dictates that the smallest amount of radiation should be used consistent with sufficient gain of diagnostic information. The kind of radiation exposure a patient incurs during dental diagnostic x-rays is not sufficient to produce any acute effect, such as a radiation burn, as may happen in therapeutic radiation (e.g. cancer radiotherapy). The timing or temporal relationship between dental x-rays and other radiation a patient receives is not thought to be relevant to risk. There is, however, a statistical risk that accumulates throughout a patient's life based on cumulative radiation exposure. To this end, local health authorities have implemented safety checks to be sure that hardware and training meets certain minimum standards of safety and effectiveness, with periodic inspections of all radiation installations.

The amount and quality of a dental patient's radiation exposure is related to the energy of the beam, duration of exposure, size of the radiation beam (collimation), as well as other parameters. These factors can be mitigated by the use of the fastest x-ray film available. The film speed currently in popular use by the profession is "E" speed film, which cuts radiation exposure 50% over the previous ("D" speed) film, with only a slight degradation of image quality and resolution. As we speak, "F" speed film is becoming available, with an additional 20% radiation savings.

The use of digitized x-ray machines, rather than the traditional use of x-ray films, is a further way of reducing radiation exposure to the patient; these machines have not yet become as popular as the traditional films due to their increased cost.

In sum, the amount of radiation exposure incurred in the course of diagnostic dental x-rays is not currently thought to present significant risk, and yields great benefit currently unobtainable any other way. The profession is making additional strides to reduce the risk even further.

Q: There are conflicting views on effect of mercury in teeth fillings. Why is it used, and what arguments are there for and against it? Are there good substitutes now? Is removing old fillings more potentially toxic than just leaving them in?

A: The mercury in silver amalgam filling material is an essential ingredient; it is used to make the alloy soft and plastic to allow it to assume the shape of the cavity in which it is placed.

The arguments against the use of mercury in filling materials are based on the common knowledge that mercury can produce toxic effects above a certain dosage. Unfortunately, a little knowledge is a dangerous thing. The fact that mercury can produce toxic effects does not mean that silver amalgam fillings cause illness. The dental profession's official position is that the implementation of proper mercury hygiene guidelines eliminates any risk of mercury toxicity from the use of silver amalgam dental restorative:

There are some "true believers" in the anti-amalgam camp, who feel that they are privy to information that has somehow escaped the members of the dental profession. There is also the attitude that a little extra precaution "couldn't hurt". This stance has the potential for dramatically increasing the cost of delivering health care while not delivering any improvement in safety or effectiveness of dental restorative care.

The material usually suggested as an alternative to silver amalgam restorative material by the anti-amalgamists, bisphenol A diglycidylether methacrylate-based resin, has lower tensile strength, lower compressive strength, lower surface hardness, and greater polymerization shrinkage than amalgam and-- it's certainly no less toxic. As we have said, a little knowledge is a dangerous thing. (BTW, it's safe to use, but we thought bisphenol A diglycidylether methacrylate would catch your eye;-)

Although removing old amalgam fillings will create a greater exposure to mercury than leaving them in place, this is more of an issue for dentists who engage in this activity all day. It poses no known risk to the patient, whether leaving them in or taking them out.

Q: What is the amount of radiation (Skin and as well as gonadal) received by a patient being exposed to a single intra oral periapical radiograph?

A: Skin radiation dose varies widely depending upon technique, cone length, collimation of beam, kilovolt peak (kvp), milliamp-seconds (mas), and choice of x-ray film emulsion. Further muddying the waters is the introduction of digitized x-ray transducers and a new faster film emulsion in the past few months.

The latest study we have seen (conducted in Greece in 1998) puts the skin exposure between 0.6 and 3.6 milliGrays (60-360 milliRADs) per periapical (e-speed) film. Gonadal dose is considered insignificant, due to the compulsory use of x-ray shielding lead aprons.

Follow-up question: Thanks, but I was interested in a comparison of background radiation from sunlight, T.V, computers, etc. to radiation from dental radiographs.

A: If we find the information about ionizing radiation from those other sources, we'll let you know (remember, we're dentists-- not television or C.R.T. technicians). Still, it is easier to quantify radiation dosage of a single dental periapical film than it is to quantify dosage from these other sources. Radiation exposure from cathode ray tube appliances will depend on tube shielding, tube type and size, position relative to tube, distance from appliance, and cumulative time of exposure. This introduces far too many variables; you can't say, for instance, that one periapical x-ray is equivalent to watching 4 hours of television. Dentists are fond of saying, for instance, that the absorbed dosage of ionizing radiation from one full set of intraoral radiographs is the biological equivalent of absorbed cosmic rays from one transatlantic air flight. This is more an appeal to the patients emotional acceptance of radiation exposure in one venue versus another, rather than a precise equivalence.

Q: What are the options for materials to get a cavity filled? Is amalgam as harmful as people project it to be? What are its pros and cons?

A: When a tooth is broken in any way due to either decay or trauma (or both), the tooth generally requires a "restoration". What is referred to in the vernacular as a "filling" is just one type of restoration. There are other types of restorations, such as crowns, which by their nature require different materials than intracoronal restorations (fillings). What we're getting at is that the specific conditions that present will sometimes dictate the material that is appropriate to the application; these materials are not necessarily interchangeable or at the whim of either dentist or patient.

That being said, the materials used for intra-coronal restorations include silver amalgam, autocure composite resin, light-cured composite resin, CAD-CAM milled resin (CEREC), cast gold, direct gold (gold foil), cast ceramic, glass ionomer cement, silicate cement (archaic), and unfilled resin (archaic). The physical properties of these materials are diverse and could fill several books, so we won't expound on these issues.

Suffice it to say that your dentist is qualified to discuss the materials available and whether they are appropriate to your specific needs. As we've noted before, mercury toxicity is currently believed to be a non-issue. Choice of materials should be based upon their physical and cosmetic properties. Toxicity issues are examined for all materials before they are approved for clinical use.

Q: I have four amalgam fillings and the rest are composite. I have been anti-amalgam for years but two years ago my then-dentist talked me into silver fillings because they last longer. I regret that decision and have renewed my desire to have them taken out after reading about the negative effects mercury has on the body with its probable cause of Alzheimer's disease, kidney and liver disease, etc. The then-dentist suggested I do not remove them. I have heard that unless you actually experience mercury poisoning symptoms that it is not wise to have them taken out casually, only if they really need to be replaced because of breakage. Psychologically, I am bothered by having them. It may be false reasoning, but, it seems it's not worthwhile to go to the dentist at all for the long run unless you are able to have all work done with either porcelain or gold... as all other filling materials wear out quickly (composite/'temporary' fillings) or are quite toxic (mercury). What is the truth with all this? Is the A.D.A. OK with pushing silver fillings or should I believe what the scientific facts are regarding the extremely high level of toxicity if mercury and its effects on the human nervous system and organs?

A: The real truth is known only to God. Unfortunately, mere mortals such as we must rely on observation and deduction. Beliefs, such as being "anti-amalgam", are in the realm of theology (to be charitable), and make truly dispassionate and impartial observation impossible.

Here then are the current thoughts of the dental profession at large who, like it or not, is in a better position to acquire and interpret the available epidemiologic data than Rodale Press, or anyone else who has a deep emotional stake in promulgating conspiracy theories:

  1. Exposure to sufficient levels of elemental mercury will evoke toxic effects in the neurological, hepatic, hematopoietic, and renal system. The same can be said for inorganic mercury compounds, and especially organic mercury compounds.
  2. Mercury toxicity, both subclinical and overt, has been demonstrated in some dentists, whose occupational exposure to mercury is many thousands of times that of the general population
  3. There has never been a recognized clinical study that has ever statistically correlated the presence of silver amalgam dental restorations and any acute or chronic toxicity, including any relationship to chronic degenerative disease.
  4. The American Dental Association has no financial or legal interest in "pushing silver fillings". They will happily accept advertising dollars from any dental materials manufacturer. There is no liability issue either, for dentists or the ADA, in continued use of silver amalgam, until or unless scientifically acceptable new knowledge makes this practice constitute negligence.
  5. There have been several legal precedents where dentists have been charged and convicted in the unlawful practice of medicine for removing silver amalgam fillings for the purpose of treating or ameliorating disease outside the scope of their license (e.g., multiple sclerosis, Alzheimer's Disease). There is also a reason why you don't see neurologists and rheumatologists clamoring for amalgam filling removal.
  6. Some dental materials proffered as alternatives to silver amalgam for restorative use have been shown also to be toxic when viewed in clinically inappropriate ways.
  7. There is no shortage of unscrupulous charlatans who are more than willing to take advantage of vulnerable persons desperately grasping at straws. Whether a person is suffering from some disease that has proven refractory to "mainstream" therapy, or is merely laboring under the belief that he can stave off the approach of aging or death, he is an easy mark for practitioners who are perhaps a bit too dissatisfied with their bottom line.

Don't be so quick to dismiss your dentist as uninformed. He has spent many years training to be a dentist, and has spent many years acquiring knowledge during his practice. It is also mandated by law that he must continue formally educating himself with courses and seminars in order to maintain his license. If new knowledge relating to mercury toxicity is forthcoming, he will be the first to know; his patients will be the next.

Q: The so-called "root canal cover-up" is discussed at length on websites found by entering those terms in any search engine. Adherents of the "root canal cover-up" theory propound that root canal should be eliminated as a procedure and replaced by tooth extraction and implant--the reason being that after root canal therapy, according to their theory, bacteria still exist in the tooth's tubules and eventually travel to other parts of the body where they can start, or contribute to, serious ailments, such as heart disease, especially when the body and its auto-immune defenses happen to be weakened for one reason or another (this is the so-called focal infection theory).

This matter should be of import to everyone, dentists included (and not only endodontists), because anyone may at any time be in need of RCT.

A medical theory is either proved or disproved by clinical tests--and not by tautological references (i.e., references to similar claims unsupported by such tests), nor by references to the experience of the population at large (which is meaningless because it can be misleading), nor by any consensus of opinions if these opinions are unsubstantiated by clinical tests.

The clinical tests in question must in turn be valid. That is, they must be conducted properly (double-bind with placebo and significant numerical sample) and be repeatable by others for eventual verification.

Elements such as the credentials or character of a theory's proponents or detractors, or the date when the theory was first advanced are irrelevant to any discussion of that theory's validity. Adherence to, or refutation of, a theory should never be a matter of faith.

So the ONLY question is: by whom, where, when and how has the "root canal cover-up" theory been disproved, if at all? In other words, what is the bibliographic reference to the results of a valid clinical test refuting that theory (author; title; journal; volume, issue and page numbers)?

Anyone who argues against that theory without having read such an article simply does not know what he or she is talking about.

Anyone with a modicum of common sense should hope and pray--as I do--that the theory in question is wrong: after all, the alternative to RCT is more costly, complicated and drastic. However, this does not mean that the evidence should be denied because of wishful thinking.

Surfing the web, I have seen scores of references to academic articles relating clinical tests that support the theory (on the Websites of its proponents) but, distressingly, not a single reference to the publication of a clinical test refuting it. So I am asking anyone, any dentist, to please give me the bibliographic reference to an article stating the results of a clinical test that invalidates the theory. That--and only that-- can be considered a disproof of it, anything else is superficial babble (needless to add, given their obvious conflict of interest in the matter, the opinion of endodontists should be considered biased and worthless unless substantiated by a reference to an article publishing the results of a valid clinical test).

A: Your point is well-taken; the automatic assumption that long-held and cherished beliefs are true and beyond question can lead to unfortunate results. However, the "root canal cover-up" theory is not the first coming of the focal infection theory, nor will it be the last. In the 1930's, the common belief was that a localized infection somehow transmitted its contagion throughout the body, causing systemic disease. This theory was used to discredit the safety of endodontic therapy at that time.

These days, the focal infection theory has its vestiges in the phenomenon known as anachoresis--that tissues with a history of prior damage can attract blood-borne bacteria, leading to serious consequences. That is why antibiotics are commonly administered to dental patients undergoing certain procedures if they have a history of heart valve disease, glomerulonephritis, or orthopedic implants.

Dentists will tell you intuitively (not scientifically) that bacterial biomass in the mouth and within oral tissues is overwhelmingly greater than any residual bacteria in an endodontically treated tooth. That is not to say this bacterial load cannot lead to systemic disease, just that it would sooner result from the comparatively greater bacterial load outside the teeth than that found within these treated teeth.

As you have already noted, the alternatives often given for root canal treatment are more costly for the patient, and more lucrative for the dentist. As you also have noted, the reputation or motivation of those on either side of the argument are irrelevant to the facts. However, the cost differential, and the potential for personal gain will influence the vehemence of those with the most to gain. We're far too cynical to think they are motivated by altruism.

Please be mindful that research dollars are in short supply, especially when re-investigating theory that has become, rightly or wrongly, accepted as true. Let us know if you find the references you seek.

Q: I've read about the dangers to one's immune system from root canalled teeth due to the impossibility of making it sterile and the subsequent leaking into the bloodsteam of toxic bacteria. I've already had 3 and now need another in a molar and am thinking of having the tooth pulled instead. Any opinions? Anyone familiar with the work of Dr. Weston Price and the book by Dr. George Meinig entitled "Root Canal Cover-up Exposed"?


A: Suffice it to say that the consensus of opinion runs counter to those of the esteemed Drs. Price and Meinig. Although we have heard of Dr. Meinig's book, we have not personally read it.

Because the potential for the dissemination of bacteria from a root canal treated tooth is statistically insignificant when compared with that from other body sources (e.g., gums, bowel, gastrointestinal tract), there is little support for any theory that may associate chronic degenerative disease or any other morbidity to the presence of root canal treated teeth.

As to the course of action that is most appropriate in your case, we would defer to the opinion of your dentist. In general, it is preferable to treat a tooth in order to retain it if it is salvageable. If root canal treatment is indicated in order to acheive this goal, it is totally consistent with proper dentistry and good general health.

Follow-up comment: It's not surprising that the "consensus of opinion" runs counter to something that would call into question such a profitable and possibly damaging practice. That would take courage and integrity. So much easier to ignore it. His (Price's) experiments could easily be dupicated but they haven't been for the reasons above.

And what's with the silence from the ADA on mercury amalgam when it's use is banned in Germany and Sweden. A poison that has strict laws for handling and disposal but is OK to put into people's mouths. Nevermind, that consensus thing again.

A: The alternatives to root canal (extraction followed by placement of a prosthesis) are no less lucrative than root canal treatment itself; even applying a cynical litmus test, there is little financial incentive for dentists to recommend root canal, but only its clinical merits.

We would suggest that you not be too quick to dismiss the value of consensus; from the biblical minyan to the modern judicial system, the concept of consensus acknowledges that the collective knowledge and wisdom of many is preferable to that of any single individual. While there is the rare visionary who sees truth that evades everyone else, they are quite rare. More often than not, the person who goes against popular opinion does so either because he is either misinformed, or is by nature a contrarian and enjoys playing the iconoclast, or even is motivated by the mercenary intent you would ascribe to the members of the dental profession.

That mercury can demonstrate toxicity is not disputed, but so can innumerable other therapeutic drugs, devices, and materials when used in inappropriate ways. Even the reviled Thalidomide, banned in most countries since the discovery of its potential to cause birth defects, is re-entering the marketplace as a potential life saver in many disease states due to its anti-angiogenesis properties.

That fact that amalgam is banned in Germany and Sweden is not de facto proof that this is medically justified. It is often more politically expedient for lawmakers to capitulate to a vocal few than to investigate the facts. No American regional chauvinism here; even in our beloved New York, a misguided bill that aims to regulate dental amalgam use is making its way through the state legislature.

In any case, the dental profession is not the monolithic political block many think it is, and this is not a case of the enlightened alternative medicine believers versus the big, bad ADA. We are all individuals, and hopefully posess the intelligence to sort through the facts on our own, if we so choose. That does not mean it is wise to rashly dismiss the truth as it is believed by others, even if it is the majority opinion...

Q: We are currently looking for a new dentist. I heard that the source of the water used during dental procedures is very important. I have also heard that the best source is bottled water changed for each patient. Is this correct?

A: Water quality has become something of a controversial issue of late, largely due to misunderstanding and (if you're of a cynical bent) due to the secret motives of certain commercial concerns that stand to gain by spread of misinformation.

The source of water is seldom the issue, since most dental offices derive their water from the same source as their patients: the municipal water supply. As such, dental patients are not exposed to any type of microbial content that they are not already exposed to if they use tap water.

Modern dental equipment is basically a closed system between the municipal water source and the patient. All equipment manufactured within the past twenty years has factory installed non-retraction valves, which prevent the backflow of oral bacteria into equipment lines. As such, the only bacteria in the water coming out is of the same nature as the bacteria coming in.

What may be a legitimate concern is the potential for bacterial growth in standing water within the narrow-diameter plastic dental tubing in the equipment. This is not qualitatively different from the bacterial growth in municipal water mains and household plumbing, but merely a quantitative effect of the small-bore conduits. Although much is made of adhesion by bacteria to tubing walls due to the increased effect of hydrodynamic laminar flow effects, it is logical to point out that any bacteria firmly attached to tubing walls is not conveyed in the water. A simple periodic flushing of water lines, which is a routine that all dentists should practice, is sufficient to reduce the level of free-floating bacteria in the contained water to hygienic levels.

There are many dental manufacturers and general contractors who stand to gain much by the advocacy of laws to compel dentists to install expensive equipment to cure a problem that has not been shown to exist. There are also members of the dental profession who have seized upon this opportunity to make unsubstantiated claims of superiority in this area. In short, the emergence of this issue is not a random discovery of science.

For the relatively few patients that are immunocompromised, quality of water is more of an issue, but this would apply in any environment, not just the dental office. For almost everyone else, a more legitimate concern is the skyrocketing cost of delivering health care. The dissemination of untruths such as baseless concern about dental unit water quality may seem like a consumer rights advocacy issue, but it is really not...

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