Are there any tooth-coloured materials that are free of BPA and estrogen-mimicking agents?
This question was submitted by a general dentist: My patient requests that her tooth-coloured restorations be free of BPA and estrogen-mimicking agents. Can you suggest any tooth-coloured materials and cements that meet those criteria?
Dr. Omar El-Mowafy, Professor and Head of the Restorative Dentistry at the University of Toronto, provided this quick initial response:
Bisphenol A (BPA) is an organic compound with the chemical formula (CH3)2C(C6H4OH)2. It is widely used in the industry when making plastic products.
Tooth-colored restorations that are Bisphenol-A-free would automatically exclude almost all resin composite restoratives and their corresponding bonding agents. Therefore, in this case the choices would be limited to glass ionomer restoratives (in case of Class 3 or 5 direct restorations) or indirect restorations made with porcelain products (inlays, onlays and crowns) and cemented with glass ionomer cements. Some of the newer porcelain products, such as zirconia-based ones and ones based on lithium disilicate, are adequately strong to the point that a glass ionomer cement would work well with them without the risk of pre-mature fracture.
Follow-up: What further information would you like on this topic? Email us at jcdaoasis@cda-adc.ca
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Interesting. Thank-you.
Very interesting. I am not sure where Dr. Omar El-Mowafy is getting his information, but last I checked, most dental resins are BPA free. Sealants were the biggest ones to contain BPA, and many newer resins do not contain BPA. I checked my restorative materials years ago, even before the BPA scare hit the public, and my composites and bonding agents are all BPA free.
There are composite products out there that are not bisGMA based and therefore have the potential to be truly BPA free. Canadian company DiamondCrown is one such brand (no affiliation). The base materials may not be any safer but just less media attention. The true answer is better research and testing standards that include estrogen effects and the like rather than LD50 and carcinogenic testing.
Of course, then I read my no-sugar added snack and see grape juice and corn syrup in the labels…
I have used Diamond Crown several years ago; however, its clinical performance in my experience was not adequate for long-term restorations. Not sure if anyone else has feedback on this material. I have used Admira made by VOCO in Germany, and found the material performed well. I am yet to be guaranteed that it is 100% BFA free.
I have checked with 3M which sells a number of resin products and they claim to be BPA free. Now we are all asking the question: who is doing the research on these product claims?
Bisphenol A (BPA) is one of the chemicals involved in the synthesis of Bis-GMA monomer. Therefore any product that contains Bis-GMA will potentially leach BPA into the environment as an impurity remaining from synthesis reaction or degradation product. If you don’t want to take risks you should completely avoid Bis-GMA-containing resins (cement, sealant, restorative…). This however (and unfortunately) does not mean that the by-products of other dental monomers will not have estrogenic effect. There is some modest research being carried out in this field, and some companies are trying to develop BPA-free resins.
There is a misconception in dentistry just like any other industry that if a manufacturer makes a claim it must be true. When dental manufacturers claim that their products are BPA FREE what they really mean is that BPA is not an added ingredient. However, since bis-GMA and bis-DMA are both derived from BPA there is always potential for BPA to be present as a contaminant. Furthermore, it has been demonstrated that bis-DMA can be degraded by salivary enzymes to BPA. While bis-DMA is only found in some products, bis-GMA is found in most resins. bis-GMA does not become degraded to BPA in saliva. However, dental manufacturers cannot assure purity since most of them do not manufacture their own bis-GMA. For the most part it is purchased from large chemical manufacturers. For detailed information on this topic I recommend reading this post from the ADA: http://www.ada.org/sections/scienceAndResearch/pdfs/PPR_MARCH_2013.pdf
if these products contain bisphenol A, i would suggest that we need a legal opinion as to possible litigation from irate patients who may attribute their cancer to our fillings…..
I challenged several manufacturers 5 or 6 years ago and they wrote letters claiming these chemicals BPA and BPS had all been removed from there products and if there was a slight amount left it was rendered inactive by other additives???? Who is telling the truth??????.
Now I am really confused as my 3M rep is quite positive there is no BPA. Should we contact 3M directly, get the association to check for us, maybe seek legal councel??
i spoke with CDPA (canadian dental protective association)and i was advised that since health canada approves composite restorative materials then we are fine to use them….
apparently the bpa is still in cans but has been removed from baby bottles….
so the concern seems to be more with the young!
The ADA article:
http://www.ada.org/sections/scienceAndResearch/pdfs/PPR_MARCH_2013.pdf
offers a good review of the topic and adds some common sense to the fears about BPA release.
Yes some manufacturers have released statements stating their products do not contain BPA, see:
http://www.ultrasealxt.com/pdf/press_release.pdf
But the question asked was not just about BPA release. What else comes out of the resins?
One thing all dentists can do for their patients is to light cure their resin restorations properly as it is well established that undercured resins release more chemicals such as camphorquinone, ethylene glycol dimethacrylate, HEMA, 4-N,N-dimethylaminobenzoic acid ethylester (DMABEE), triethylene glycol dimethacrylate (TEGDMA), Tinuvin P , and bisphenol- A-polyetheylene glycol dimethacrylate (BisEMA).
.
See: Dent Mater. 2012 Nov;28(11):1146-53. doi: 10.1016/j.dental.2012.08.006.
Correlation of the degree of conversion with the amount of elutable substances in nano-hybrid dental composites.
http://www.ncbi.nlm.nih.gov/pubmed/22940188
This means buying the correct curing light for the resin you are using and then using the light properly.
Dr. Debra Mitchell commented the following:
We should know the content of BPA present in fillings and sealants commonly used in dental restorations.