THROUGH SERUM ANTIBODY TESTING
©2004 Suzin Stockton - (from Issue #2 of Cavitations Plus Quarterly newsletter)
Compatibility of various dental materials can be determined, with varying degrees of accuracy, through different testing methods. These include Applied Kinesiology (AK), ElectroDermal Screening (EDS) and reactivity testing, an immunological testing procedure using blood serum. The first two testing methods provide indicators of the body's energetic response to samples of intact dental materials. In AK, a strong or weak muscle response will be interpreted as an indication of whether or not a particular material is biocompatible. EDS measurements utilize computer technology and are more quantitative, yielding more detailed information about both the degree and nature of the body's response to a given material.
Materials reactivity testing is unique in that it examines the body's response to corrosion by-products of components of dental materials, rather than its response to the complete, intact material. Such reactivity testing was pioneered by Walter J. Clifford, whose "Clifford Materials Reactivity Test" is actually a new application of an old technology, the "precipitin" testing method, first used almost a century ago to detect and identify specific bacteria involved in infections. The body produces various antibodies (chemical bullets) in the form of immunoglobins to combat these bacteria, as well as to counter viruses and a wide variety of toxic substances. It is this immunological response to toxic exposure that is detected through reactivity testing. Such toxic exposure will typically cause the body to generate IgG (Immunoglobin G), IgM and IgA antibodies. This is different than an allergic response which generates IgE antibodies.
The Clifford Reactivity test detects serum antibodies which the body has formed against specific chemical groups (antigens) as a result of prior exposure to them. Such detection is based on antigen-antibody precipitin observation where a sample of the challenge material (a specific chemical group or family, such as acrylates, urethanes, nickel, mercury, etc.) is mixed with the patient's blood. Adverse reaction to the chemical group is indicated by the formation of an immune complex which will precipitate out of solution and settle to the bottom of the test vial. Such precipitin testing is in common use in many laboratories today for the purpose of confirming microbial or toxic exposure. It is well established and documented that exposure to materials which have previously caused antibody formation will result in the presentation of clinical symptoms in the patient. These symptoms can manifest as dysfunction in any organ or system: They may express as autoimmune conditions, disorders of the nervous system, gastrointestinal upset, elimination problems, etc. Any substance found to evoke an immune response should not be placed in the body from any source.
While more than 1650 trade-name dental products are evaluated as either "suitable" (S) or "not suitable" (NS) in the Clifford test, such evaluation is not made using the products themselves, but rather using the corrosion by-products of chemical groups which they contain. When an antibody is formed in a patient's blood in response to a particular "challenge group" of
chemicals, this information
is fed into a computer database containing
information about which dental products contain
the offending group. The test results will
rate both specific dental products and general
chemical groups as either S or NS. Only when
a product contains the offending chemical
groups in "ionizable, dissociable or
off-loadable form" is it placed on the
NS list. Therefore, a product containing
an NS chemical groups, such as aluminum salts,
for example, may nonetheless be rated as
S. In such an instance, the S rating would
be given if the aluminum is considered to
be present in a form which is chemically
bound within the product, with no significant
amount of ionization expected -- or an insignificant
amount of the metal is present in the material.Aside from listing materials and chemical groups as S and NS, the test gives an indication as to whether the antibody formation response is a strong or weak one. A strong response simply indicates a recent exposure. It does not correlate with intensity of clinical symptoms.
In summary, Clifford testing examines a patient's response to the corrosion by-products of major ionizable components in a particular dental product as measured by antibody formation in the blood. These corrosion by-products are the result of material decomposition or breakdown in the oral cavity. The testing system assumes that toxic exposure will stimulate an immune response, but acknowledges that such response will not be seen if the patient has had no prior exposure to the substance being tested. In such instance, no antibodies will form, and the test will yield a false negative result. A false negative may also be produced when antibodies are formed at a level too low for the test to detect. Such a weak response may occur in patients who have been on immune suppressive therapies, such as corticosteroids. Another possible cause for a false negative would be that the patient has developed immune-tolerance to the antigen. False positives can also occur. This is thought to result from 'cross reactions' where antibodies against one kind of challenge cross react with other challenges, a condition which may occur in the body, as well as in the test tube. Frequency of both false negatives and false positives is reported by Clifford Consulting as being less than 5%.
Clifford Reactivity testing of more than 12,800 patients indicates great variability among people in response to particular dental materials. It shows that even the "noble" metals are not well tolerated by all people, as 1% of the population has been found to have problems with gold and 25% with silver. Varying degrees of intolerance to composite and ceramic (non-metallic) materials occur among different individuals as well. There is no one restorative material that is universally compatible, nor any that are totally benign in their effects. The stated goal of Clifford testing is to aid in the selection of "least offensive" materials.
Clifford in-house evaluations of accuracy and reliability of the test are reported to be approximately 90%. Reproducibility of test results on similar specimens is said to be in excess of 95%.
The test evaluates a wide variety of dental products: composites/acrylics, glass ionomers, cements and adhesives, bases, liners, sealants, etchants, denture materials, orthodontic materials, root canal materials, porcelains, precious and non-precious alloys and more -- 23 categories in all. While Clifford Reactivity testing can be an excellent tool for alerting the practitioner to the potential reactivity of a given product for a given patient, it should be understood that some S materials may be electroactive against each other and/or inappropriate for placement due to poor mechanical performance. The testing does not take these issues into account.
Since reactivity testing and EDS (ElectroDermalScreening) evaluate dental products differently, the use of both procedures may be desirable for the purpose of cross-validating results. One method may pick up on something that the other has missed. Any product found not suitable by either method should be avoided. There is frequently a high degree of correlation between the two testing methods, so discrepancies should be few in number.
While an S rating on the Clifford Reactivity test does not guarantee that a patient will be able to tolerate a particular dental material, there is a high probability that this will be the case. If the material in question is also tested by EDS and found compatible, then the chances of the patient being non-reactive to the material increase. Certainly both tests help take the guess work out of material selection and decrease significantly the chances of an adverse reaction on the part of the patient. Bear in mind, however, material incompatibility cannot be totally ruled out based on any test. This is always a possibility that must be kept in mind by the practitioner and the patient.