Materials Reactivity Testing – Part II

This month I continue my interview with Walter “Jess” Clifford on dental materials reactivity testing. Jess is the founder of Clifford Consulting and Research (CCR) and is one of the world’s top authorities on dental materials. Using antibody detection in a patient’s blood serum, CCR Labs tests for material compatibility.


As a Whole-Body Dentist, why am I concerned about dental materials testing?

As Jess so aptly explained last month, “Traditional thought among dentists suggest that any and every product is safe and effective for any and every patient, especially if it carries a ‘Seal of Approval’ from some regulatory or professional body. The acceptance and approval process for restorative materials has very little to do with long-term sustained biological safety. “


In the last month’s newsletter, we learned that the chemical constituents resulting from corrosion, galvanic currents and out-gassing from dental restoratives are often absorbed and may lead to serious physiological impact and tissue build-up. These, in turn, interfere with normal activity in the cardio-vascular system, the digestive process and gastrointestinal tissue, neuralgic function, musculoskeletal strength and coordination and pulmonary efficiency. Jess comments that, “Few healthcare professionals would associate dental materials with neurological disorder, skin problems and digestive issues.”


Jess, we have covered the issue of dental materials safety, how materials are traditionally tested, and your unique observations regarding materials selection and bioactivity as well as how CCR Lab tests for material compatibility for over 5,800 dental products.


Patients often present with many different materials in their mouths – amalgams, composites, gold, nickel, etc. Are there potential problems with different materials in the mouth, even if they are ‘Non-Metal?’

Without question, the answer is YES. It is vitally important to note that there are no such entities as metal-free dental products. I know that ‘metal-free’ is an important buzz-word in dental product advertising and in practice promotion. However, when I see such claims in advertising, I have to wonder where these professionals took their basic undergraduate chemistry and physics training.


You will recall that basic chemistry mandates that wherever there is an anion (organic compound, silicate, resin or whatever), there must be a counter-balancing cation. Cations are nearly always metals or metalloids. Even dental products must abide within the principles of chemistry, physics and nature. Whether the product being considered is a glass, porcelain, ceramic, resin composite or even a simple denture acrylic resin, there are always metals present.


However, the absolute presence of metals is not the proper question to begin with. What we really need to know is what form the metals take and how readily releasable the metal components are.


There are many products which do not contain easily released fully-reduced ‘shiny’ metal. They will always contain metal in various states of oxidation and combinatorial chemistries. Simple consideration of sand (the basic component of glass) usually finds that it contains aluminum, barium, boron, lithium, sodium, potassium, calcium, iron, magnesium as well as traces of other metals and metalloids. Our skeleton naturally contains various metals in chemical combinations, including between 2%-2.5% aluminosolicate.


The point is made that we do not need to recoil in abject fear when we hear the word ‘metal’ used in relation to dental products. It’s there.


If the patient can safely store food or beverage in a glass container or cook and eat from glassware, then there are forms of metals which are not going to utterly destroy good health.


That said, there are various forms of both metals and organic molecules which can enter into new chemical interactions if they are brought together in the mouth. They need not touch physically. Their connection can be formed through body fluids as well as both soft and hard body tissues.


The chemical bonding qualities and physical nature of certain elements and compounds will cause them to exert pressures and force upon certain other elements and compounds. The degree of the pressure or force is dependent upon how dissimilar the components are in their chemical nature, composition and makeup.


Electrons will be snatched from one and held by the other, creating charged components that do not behave like the natural component in resting or steady state.

We have a voltage created, sometimes called an electromotive potential. When electrons move in such natural or biological circuits, we see a galvanic (electrical) current flow. The newly charged components which either gained or released the electrons may not remain stable and bound as normally expected. Sometimes, the electrical flow between dissimilar materials within the mouth can be great enough that the electrical current flow can actually create a physical electrical burn in surrounding tissues.


While frankly reduced ‘shiny’ metals and metal alloys are most prone to this sort of activity, ceramics, glasses, porcelains and resins can also do the same thing. In the mouth, the use of dissimilar materials can result in one material attacking the integrity of another and the abnormal release of chemical components which was neither anticipated nor desired.Patients will sometimes report a burning sensation in the mouth, or strange taste or odors. Others describe the release of the chemical constituents as numbing with loss of taste, while yet others will present with sores or tissue discolorations due to infiltration of the tissue by the abnormal chemical components moving through the tissues.


Do you have any general advice for dentists whose patients have not had a materials reactivity test?

It is always wise for the dentist to stay within the same products or product families when doing follow-up treatments as those used in prior treatments. Materials selection should minimize the dissimilarity of components. For example, it is best not to use a cementing or bonding agent based upon aluminosilicate chemistry to secure a crown or inlay which is based upon zircate chemistry.


Adverse interaction can weaken or otherwise lead to the failure of dental work which was truly fine in its physical implementation. If one type of dental bridge alloy was used and has given good service, the dentist would want to continue in the use of that specific alloy or one very similar to it. Comparing percentage of gold between alloys is a poor mechanism of insuring compatibility, as the other metals alloyed with the gold component may be vastly different.


Any general advice for patients?

Patients can do themselves a very great service by requesting copies of their dental treatment records. In our mobile society, it is highly likely that more than one dentist will provide care to the patient over the years. Having a reliable record of materials previously used with good success will be very helpful to the new dentist. Conscientious dental professionals will not mind sharing treatment records with the patient, and it is a fine service to the next professional who needs to make judgment calls in designing ongoing treatment plans down the road. We always send two copies of our compatibility test report – one for the doctor and one for the patient.


Jess, I know your lab is releasing a new testing panel this fall that will be oriented to testing materials used by physicians in orthopedic and implant surgery. Can you comment about possible interaction of dental materials with implanted materials elsewhere in the body, such as in the hip or the knee?


The same principles apply to interactions between dental and orthopedic materials as between dissimilar dental products.

Since they do not need to physically touch to interact, if they have sufficient dissimilarity, they can enter into a galvanic circuit between them. The usual connection is the vascular bed, although any and all body tissues and fluids can participate. Even with the newer ceramic materials being used in orthopedic implants, dissimilarity is the essential question.


It is uncommon for the dentist and the orthopedic surgeon to communicate under current common practice. However, strange and anomalous tissue reactions, implant rejections, tissue healing problems and various systemic disorders are raising the issue of adverse interactions more and more.


Selection of orthopedic materials needs to be done in a manner similar to dental materials. The body cannot distinguish between nickel found in a dental bridge and nickel in a knee replacement. The galvanic currents and the abnormal releases of components have a similar body effect.


Jess, thank you for this fantastic interview. I am always amazed at your depth of knowledge in the field of dental materials. I am sure my readers have been thrilled with your information. Dentistry certainly was easier when all you had to worry about was “drill and fill”!


Clifford Consulting and Research Inc. (CCR), headquartered in Colorado Springs, Colorado, was founded in 1988 after the invention and development of the Clifford Materials Reactivity Testing (CMRT) concept by Walter J. Clifford, who currently serves as president of CCR. CCR’s unrelenting commitment to values such as service, integrity, and innovation in promoting quality care for patients through testing and research has resulted in 17 years of rapid growth as a unique provider in the industry. CCR now offers information, services and seminars to healthcare professionals throughout the United States, as well as international locations. You can visit their website at


© 2005, Mark A. Breiner, DDS

The information presented is for educational purposes only. You should consult a qualified dentist or health practitioner for diagnosis and treatment.

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