Michael C. Goldman, DDS
BPA and Dental Composites - Are They SAFE ?
Bisphenol-A [BPA]
and Other Estrogenic chemicals found
in Dental Composite Fillings.....there is no dental material known that has no known or suspected toxic potential! They are ALL potentially toxic to some degree! But some are much worse than others!!!!
Sept. 2008
The Problem
Recently, many patients have become concerned and emailed me asking about the possible toxicity of dental composite filling / bonding materials. There has been concern that they may have hormone-like behavior. It has been reported that they contain "BPA" - bisphenol-A - which is thought to act as an estrogenic substance and is said to have endocrine-disrupting actions.
There are many questions to be concerned about this. First, if used in the teeth of very young children, could it have a hormonal effect on their development? If used in women's teeth, could it promote hormonal changes or even stimulate estrogen-sensitive cancers, like some types of breast cancers? Could it have a feminizing [estrogenic] effect on men? These are all fair and reasonable and scary questions!
Why is it important
In my practice, I see many patients that want to get rid of their silver-mercury [amalgam] fillings because they are concerned about the potential toxicity of mercury. [ All amalgam fillings are one-half made up of mercury! ] There are other articles on this site more about amalgams and mercury. When amalgams are removed the most common material used to replace them is "composite", which is basically a hard plastic material filled with tiny, powdered, tightly packed, granules of ground up glass, porcelain, quartz, silica and other materials to give it the color, hardness, and toughness it needs for a particular type of filling application.
People that are concerned enough about the toxicity of mercury to have their fillings removed and replaced, certainly don't want to get rid of one toxic material, just to have another different one put in, right? Right!
I have been looking at the research literature to try to get a handle on this difficult question. The ADA and other organizations tend to say "don't worry, it's fine".... but they have also been saying that about the mercury in amalgam for a hundred and fifty years, so who do we believe? In looking at the literature and hearing information at continuing education courses, I have begun to feel more comfortable with some general conclusions, which I will try to share here.
Present Situation
The present situation as I see it is this. With possibly one exception that I know of, all composite filling / bonding materials are just about the same chemically. They may differ a little here and there for several reasons but their basic chemistry is very closely related to each other.
Now, having said that, I have to add this. Composites are basically "plastics" as far as their chemistry goes, and "plastics" are very complicated. They are also all around us, used in almost everything we see, touch, and use every day in one form or another. The cars we drive - that used to be made of steel - are almost half made of plastics now! and so it is from our expensive filtered water bottles, to our iPhones and computers, from our baby bottles and toys to the lining inside the cans of food we buy at the market. To AVOID plastics in this day and age, is almost impossible ....you'd have to work very hard at it, indeed!
The problem with plastics being "complicated" is that the industrial processes that are involved in making them are also very complicated and complex. Many steps are involved and depending on the degree of "quality control" used in the manufacture of them, there may be more or less "impurities" produced and left in them. Impurities are undesirable chemicals that were never meant to be in there but are accidental by-products of complicated chemical reactions used to make the plastics. Or they can be undesirable by-products that are expected and known about, but not adequately and completely enough removed. You could almost think of it as the process of planting a lawn. If you do it carefully, using good seed and dirt and fertilizers and good technique, you get a good thick lush lawn with no weeds. Do it less carefully and you get weeds, brown, bare spots and so on. Still a lawn, but not nearly as good.
The other problem with it being complicated that I think of is that there are many complicated chemicals produced by the reactions so that the chemistry is much more than just what is mixed together in the beginning, because those things react with each other and produce a whole bunch of other things, sometimes only temporarily and sometimes they stay in there. So when we talk about "BPA" we are really talking about a long list of somewhat related but still different chemicals that differ slightly by brand and by quality control.....I hope I haven't just made it more confusing than ever for you!
How to make Sense out of it All
I came across what I thought was an interesting and informative research article http://jdr.iadrjournals.org/cgi/reprint/83/3/222.pdf that I will try to highlight what I think are the important points.
The authors of the paper state clearly that certainly "the release of estrogenic compounds from composite is ...undesirable" . But they researched 24 popular composite materials to determine the level of BPA's in them and the makeup of that BPA and the estrogenicity of each brand of composite tested.
Compared to a "control" sample which was not estrogenic and just used for comparison, they found a significant range among the 24 composites. Six of them were much more estrogenic than the control and the others were very close to or even less than the control. Since the control was realistically "zero" the slight variations must be, I concluded, due to slight inaccuracies in the technique or the instrumentation used to get the measurements. Keep in mind that we are dealing here with EXTREMELY SMALL AMOUNTS of chemicals being measured. Like trying to measure the length of a flea with a ruler!
Overall, they seemed to conclude that while more research should be done, the results they got, strongly suggest that the amount of estrogenic effect is VERY SLIGHT and probably negligible for humans.
Other, older, studies had also shown that the levels of BPA in composite were in the range of a hundred times LOWER than what was thought to be acceptable exposure [by the Canadian government which tends to be more strict on such issues than in the USA].
I would highly recommend looking at an article written for IAOMT -International Organization of Medical Toxicology - an excellent organization for dentists and physicians and researchers dedicated to non-toxic treatment. They are into scientifically verified procedures rather than "trendy, holistic-sounding but unproveable ideas. http://www.iaomt.org/articles/files/files276/BPA%20review.pdf
What Do I do?
First, studies like this one help guide me in the choices of which products I chose to buy and use. It helps to verify what I have long thought that good name brand manufacturers tend to have better quality control. Usually, but not always, they charge more for their products and it's worth it. 3M is one, but not the only, such good company in my view. Off-brand, generic, products, may be just as good in some cases but there's a level of trust missing with them. You never know who's actually making the stuff and it could change from month to month and still end up with the same label on it at the end! We all remember the toys from China with the lead-paint !
Another idea that seems to make sense recently to me is that rinsing well after getting a composite filling is a good idea because much of the various BPA chemicals end up in your saliva and can be washed out. And while spitting them down the sink is not the greatest thing, it's better than keeping it in your mouth to be swallowed.
Luckily, research shows that unlike the mercury in amalgam fillings, which is released constantly over years and years for as long as the amalgam is there, the BPA's and related compounds are released mostly when the composite filling is first done and chemically or light cured [hardened] , and then drops off rapidly after that to almost nothing for the duration of the life of the composite filling.
The Near Future
There is a lot of concern about composites and a lot of money to be made in the making and selling of them by dental materials manufacturers. Manufacturers are concerned about the public's anxiety about BPA and other possibly toxic ingredients and they are aware of regulations limiting or banning it in this country and in other countries. So I can't imagine it will be long before they find a way to make composites without these undesirable compounds or with levels so low that they will be almost absent.
There is one composite, as I mentioned in the beginning, that is claimed by many holistic dentists to have no BPA's. It's chemistry is a bit different than all the others as far as I can tell, so perhaps it's true. It is called Diamond Crown, Diamond Flow, Diamond Lite etc. I have recently gotten some literature from the manufacturer [or perhaps it's just the distributor], and it looks very interesting. I asked for research articles and what I got was pretty old and not really dealing with the questions discussed here. I have not, unfortunately, been able to find reliable scientific research to back up the claim of no BPA made by many of its supporters. While they claim to be "non-toxic" they don't specifically mention BPA or the sub-chemicals resulting from BPA.
Many "holistic" dentists claim it to be a fact that the "Diamond" products are free of BPA and other undesirable compounds; however, I have found nothing in the literature to back up that claim. That bothers me!
UPDATE 2009
There is a fairly new Composite material from a German manufacturer Heraeus-Kulzer, called Venus Diamond. It claims to be totally BPA-free. I wonder if they didn't buy the "Diamond..." line of products mentioned above and put a new name on them, but I'm not sure. I have not used the Venus Diamond composite. I imagine it's pretty good but I had a bad experience with Kulzer several years ago when I used another composite product they promoted heavily and it seemed to be great, but it turned out to be pretty bad! So I have very limited confidence in Kulzer even though they are a large major manufacturer of dental materials.
2011
As far as I can tell now, the Kulzer Venus Diamond is not at all related to the Diamond Crown, Diamond Flow, Diamond Lite [mentioned above] materials made by a Canadian manufacturer, I believe. I'm not sure if the Kulzer products are bpa free but searching the MSDS sheets does not indicate any bpa that I could see. The Canadian Diamond Crown, Diamond Flow, Diamond Lite composites are, I believe totally free of bpa because they are based on a very different chemistry. They are phenolic plastics, whereas the American and European composites seem to be methacrylate plastics. I hope that's helpful and not more confusing! Then there's the question of whether phenolic plastics pose a different kind of possible toxicity? Generally speaking phenolics are not good things but perhaps it it's ok in this form.
If you know of what looks like a reliable research article that shows the Diamond line of composite materials - or any other composite product for that matter - to be free of potentially toxic compounds, please email that info to me so I can share it with others!!!!
In Conclusion
It seems to me, as I have stated many times in other articles on this website [which I strongly encourage you to read], that there is no dental material known that has no known or suspected toxic potential! They are ALL potentially toxic to some degree! But some are much more so than others!!!! So while there are some legitimate concerns about specific ingredients in composite filling materials, it does seem to me that while there is some risk, that risk appears to be VERY SMALL when viewed in its proper context and when compared to other materials available to use.
An exception to this statement might be that there may be some people that could have specific - and unusual - allergies to, or hypersensitivity to the specific chemical compounds found in dental composites. That would not apply to most of us.
This article was written in the hope that it will increase understanding about a topic that seems important from time to time. Obviously it is only a part of the whole story, so if you have questions after reading this please do not hesitate to ask or email. Also, if there is a topic that you think would be helpful, please suggest it. Does this help you? Let me know.
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**********************************************Michael C. Goldman DDS
General and Cosmetic Dentistry
3815 East-West Highway
Chevy Chase, Maryland 20815Phone (301) 656-6171
More info about the following is available if you select "topics".
Holistic dentistry is an approach to dental treatment, primarily caring for patients' health and safety from both a conventional as well as "alternative healthcare" point of view. It is sometimes called "biological" dentistry or "biocompatible" dentistry. In it's fullest sense, I believe it acknowledges and deals with the mind, body and spirit of the patient, not just his or her "teeth". See Topics / Info.....
Cosmetic dentistry is about doing quality , esthetic dentistry in a way that looks natural to begin with, and furthermore, can even improve one's attractiveness through techniques such as bonding, bleaching, veneers, caps, implants and more. It can be like "instant orthodontics" in correcting crooked, twisted or misplaced teeth in many instances. Dark or misshapen teeth can be restored. Smiles that lack youthful vigor or beauty can be revitalized! See Topics / Info..
In holistic dentistry there is an effort to find biocompatible materials to use to reduce toxicity for everyone, especially the chemically sensitive. Amalgam use is avoided in holistic dentistry (" amalgam free" or "mercury free") due to concern about possible toxicity problems. Amalgam removal and replacement with natural-looking bonded materials is a common holistic dentistry treatment as well as a common cosmetic dentistry treatment. Detoxification, especially of residual mercury deposits in body tissues from amalgams is often done. Root canals are controversial in holistic dentistry and are discussed under topics. And much more....
Bleaching, veneers, bonding, caps, bridges, and implants are cosmetic dentistry treatments that are also discussed in Cosmetic Dentistry, and more...located in the Bethesda, Chevy Chase, Maryland 20815 area near Washington DC.
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