Do you know about the crown effect?

I thought I knew it all, but after I recently attended a presentation by a biological dentist, I learned some disturbing facts about crowns, that I want to share with you today.

adobe.stock/Zea_Lenanet

Most of us know about the existence of two types of crowns - metallic and ceramic - which are commonly offered to us in the dental offices we visit, if a crown becomes necessary. What I did not know, and probably many of you didn’t know either, is that there are many layers of important health information that are often not explained to us during our dental visits. My personal experience, and that of many people I know, is that when you go to a dental office you may be told that you need a crown. You agree to it, without much discussion, and then the appointment is made to have the crown placed in your mouth. At best, you are asked to choose between a metallic one, a ceramic one, or a ceramic crown with a metallic base. At most, the discussion may include information about the strength, the durability of the material, and of course the price of the procedure. What often is not discussed, and is personally most important to me, is how these materials, placed in my body, could potentially affect my health in the long term.

adobe.stock/Alexandra Gigowska

I have recently learned that the metal in the ceramic crown with a metallic base and in the entirely metallic crown, is not one type but five types, often offered in a combination between two metals (an alloy).

Here is a list of those metals:

Gold and Palladium alloy (Au-Pd); Silver and Palladium alloy (Ag-Pd); Cobalt and Chromium alloy (Co-Cr); Nickel and Chromium alloy (Ni-Cr);Titanium (Ti)

Many of you may be asking yourself why this information is important. It is important because of two major issues. The first is that your body may have an allergic reaction to one of the six metals used in dentistry and the second is the potential toxicity of the metal itself.

I want to stress that in allergies, the problem is often not so much the immediate, anaphylactic, reaction of the body to a substance, such as when you may start suffocating because your airways are closing, or your body may get covered in blisters, but the delayed immune reaction. Though immediate, anaphylactic immune reactions could be deadly if they occur, luckily they are extremely rare.

What, in general, occurs more commonly when foreign materials are places in your body tissues, is the slow immune response which builds up over time and maintains a long term inflammation.

This type of immune response may not always be obvious.

It appears that when metals are placed in your mouth they are bathed in your saliva 24/7, and this has consequences.

Small amounts of these metals are released in the saliva through a process called oral galvanization. The process occurs in acidic environment (your saliva), and it increases in strength with increased acidity (for example, any infection in the mouth increases acidity).

I will cite here the study of Zhao et al. published in 2018 in the journal of Life Sciences. The researchers evaluated the effects on zebrafish embryos when the five above-mentioned metals (Ti) or metals alloys (Au-Pd, Ag-Pd, Co-Cr, Ni-Cr) were bathed in saliva. They compared the results to controls (fish exposed to only pure, non-metal-bathed saliva). They evaluated the effects on the fish after one week, four weeks and seven weeks’ time.

The results showed that there was no difference between the two groups of fish at week one, but at weeks four and seven, noticeable differences occurred.

At the seventh week the death rate of the fish was 2-4 times higher in the metallic-bathed saliva group compared to the controls. The highest death rate occurred in the nickel-chromium group (Ni-Cr).

The reported death rate for all metals was as follows: Au-Pd - 25%, Ti - 27%, Ag-Pd - 32%, Co-Cr - 39%, Ni-Cr – 48.67%, and for the controls – 9.67%. Decreased hatchability (the number of babies born), decreased body length, heart rate changes, decreased body movements and decreased length of distance the embryos were able to swim, occurred in all metal-bathed saliva groups compared to the controls. In addition, the metallic group had the occurrence of pericardial (the sac around the heart) edema, spine curvature abnormalities and ocular (eye) problems. I wonder what happens after one, two, three or more years of exposure.

Yan et al, published in the Clinical Case Report journal in 2018, the results of a patient who had health problems after a metallic-based dental procedure, which disappeared after the metal containing material was removed.

In addition, the researchers cited the percentage of metal leaking in the saliva which they measured in 212 subjects. The highest leak occurred in the nickel group.

Results of percentage of metal released in the saliva in all groups are as follows: nickel (Ni) – 25%, palladium (Pd) – 24.4%, chromium (Cr) – 16.7%, cobalt (Co) – 15.9%.

adobe.stock/Zffoto

In addition, there might be misnomers when crown types are referred to in some dental offices. Ceramic crowns are made from porcelain which is based on kaolin clay. Therefore, porcelain and ceramic crowns should, in general, refer to the same material. However, there is a porcelain-fused-to-metal (PFM) material, which is a porcelain (ceramic) covered metallic base crown, which may be called just ceramic or porcelain when discussed with you in the office. In addition, some dental practices make a distinction between porcelain and ceramic crowns. For example, a ceramic crown (sometimes called e-max) can represent a fusion between ceramic, lithium and tin. Therefore, it might be wise to ask if the crown offered is entirely porcelain, or entirely ceramic or if any type of fusion has been used in the production of it.

In conclusion, the entirely porcelain/ceramic crowns do not contain metal. However, keep in mind, that their strength might be a bit lower than the crowns containing metal. In the end, it is always your personal decision what to put in your mouth, but please become well informed before making a decision.

adobe.stock/Igor Kali

In closing, I want to mention one new kid on the block (introduced in 1990), and that is zirconium. Zirconium is a transitional metal (e.g. part metal, part crystal) which is highly resistant to corrosion (zirconium has been found in the Sun and in S-type stars – cool giants).

Zirconium has a crystalline lattice and it is often used in the jewelry industry to

produce expensive gemstones look-alikes (e.g. diamonds etc.). In the jewelry industry it is referred to as a cubic zirconia (ZiO2) to differentiate it from the one used in dentistry where it is often stabilized with yttria (ZrO2Y2O3), is slightly translucent, and it has been reported to be strong, durable and biocompatible.

Though a reaction can occur with any foreign substance placed in the body, there are studies showing that patients reacting to titanium (usually the metal most tolerated by the body) may not react to zirconium. Titanium is often used as a tooth implants’ base, at present, and zirconium appears to be a good alternative. The biological dentist, the lecture that I attended, claimed that in his practice he had less rejection of tooth implants when he used zirconium as an implant base.

Borgonovo et al. published an article in 2017 in JDPS, about

a 98% first-year success rate of his zirconium-based tooth implants and a 95% 5 year rate. Zirconium is weaker than titanium, but it still has twice the flexural strength and four times the compression resistance of steel.

So, what I am supposed to do, if a metal immune reaction is suspected in my body? The good news is that there are skin patch tests available for metal reactivity evaluation. In addition, tooth inflammation not visible on a regular and even digital x-ray may be seen on a 3D cone beam study (a new technology).

Here is a website where you can look up a list of biological dentists in your area if you would like: www.iabdm.org (International Academy of Biological Dentistry & Medicine). The down side is that the dentists providing this high level of dental care are rare and some travel maybe needed if one desires to engage in biological dentistry.

So, my dear Reader, I suggest that you be wise and ask questions when offered a crown. Consider discussing with your dentist metal sensitivity testing if you acquire symptoms that nobody seems to be able to find the cause of or if your disease behave in an unusual way.

From my heart to yours,

Dr. Ani

Disclaimer:

Though I am a medical doctor and I share my experience and knowledge with you, please be advised that I am not your medical doctor, so you will need to seek and follow the directions of the medical professionals involved in your case. This article is purely informational and cannot be taken as medical advice.

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