When we previously surveyed dentists on the topic of bisphenol-A, we found about half of dentists were worried about BPA in dental composite and sealants.

"Patients should be told restorative treatment and material options, risks, benefits, average longevity, etc. (of composite, amalgam, castings, etc.). Then, as a well-respected lecturer sarcastically says, they can 'pick their poison,'" said a Maryland dentist. "I wonder if, a few decades from now, we will still see the short longevity composites to be as safe as amalgam is and was for 160 years."

Read more: Dentists Change Dental Materials over BPA

So we asked dentists who should be responsible for the safety of dental products. One third said the FDA, one quarter said dental labs should police themselves, and 41% said dentists should take responsibility.

“My local lab is placing 'made in America' on all of the return cases for the patients to see,” mentioned one dentist.

“Too many dentists are accommodating low dental insurance payment schedules by buying their dental materials and laboratory fabrications that are too cheap," complained another. "It doesn't seem to matter that it compromises the health of the patient."

Read more: Lead found in dental crown from China: Dentist Survey Results

On the other hand, half think we still need more research. "The ADA must respond only to true science," one dentist declared.

BPA, an ingredient in some dental sealants and dental composites, has been getting a lot of bad press… this could be a serious dental management issue for cosmetic dentistry in the not-too-distant future.

When asked if the ADA should take a stand against dental bisphenol A, here’s what dentists had to say:

• "The ADA should conduct a thorough Scientific Study so we do not have another 'amalgam controversy.'" (Kentucky dentist)
• "Whatever the studies show, the ADA needs to get that PR out to the public… If we say nothing, then the only voice the public hears will be other voices." (General dentist)
• "Look into this more fairly before alarming everyone, perhaps unnecessarily." (New York dentist)
• "I think that we need all appropriate in vivo experimental and clinical studies in order for the proper authorities to rule one way or the other."
• "BPA is linked to female issues. We need to be preemptive, even if there is a doubt. What are they waiting for, a return to amalgams?" (Michigan dentist)
• "I have a one year old and we make sure never to have him use bottles or other items made of BPA. Most companies that produce products placed in babies mouths are removing BPA from them (bottles, pacifiers, etc). Therefore, why should dentists continue to use dental sealants with BPA? It doesn't make a whole lot of sense." (Ohio prosthodontist)
• "It is my understanding that BPA itself is not an ingredient in composite materials, but bis-GMA, which is made from BPA. The amount of unconverted BPA in dental materials is almost undetectable and has not been shown to be a health threat. There is also no better alternative material for long-term restoration of the dentition."

Read more: Dental BPA: ADA Stance on Bisphenol-A Divides Dentists

Because children may be particularly sensitive to the hormone-like effects of BPA, this issue is of particular concern for the pediatric dentist.

Read more: Bisphenol-A in Dental Composite Worries Dentists

There's more than just a passing similarity between the issues. Both mercury and BPA are known to be harmful in certain quantities. Both can be found in some dental restorations. And in both cases, the scientific evidence is inconclusive about how much BPA or mercury these restorations release into the human body.

Let's also note that there are significant differences. Mercury is a metallic element that is poisonous in its raw form. Bisphenol-A is a plastic additive that appears to have an estrogen-like effect on cells.

When it comes to possible toxic effects of BPA, here's what the ADA says:

The ADA believes any concern about potential BPA exposure from dental sealants or composites is unwarranted at this time. When compared with other sources of BPA, these dental materials pose significantly lower exposure concerns.

Published in the ADA Journal in 2006, the research study Exposure to bisphenol A from bis-glycidyl dimethacrylate–based dental sealants found measurable amounts of BPA in patients' saliva after the application of dental sealants. Though the study concluded, "Sealants should remain a useful part of routine preventive dental practice, especially those that leach negligible amounts of BPA," it also recommended further research:

Clinical Implications. Dental sealants may be a point source for low-level BPA exposure at levels that show health effects in rodents. Further research is required to determine whether human exposure to BPA at these levels causes adverse effects.

In a November 2008 statement, the ADA acknowledged that BPA can be found in some dental products:

BPA may become part of dental sealants or composite resin filling materials in three ways: as a direct ingredient, as a by-product of some ingredients in dental composites or sealants that may have degraded, or as a trace material left-over from the manufacture of some ingredients used in making dental composites or sealants.

But an ADA newsletter from April 2007 seems to contradict that:

BPA is a chemical found in many hard plastics and used in resins that line food and beverage cans. Although some believe BPA is an ingredient in dental sealants and composites, it isn't, although there's some evidence that some dental sealants and to a lesser extent composites may contribute to low-level BPA exposure, probably through the action of salivary enzymes on a minor ingredient. We see no cause for concern at this time but do look forward to the results of a review of a draft report on BPA safety by an independent NIH panel of endocrinologists, statisticians and biologists.

While the possible estrogen-like effects of BPA are news to most consumers, the ADA and concerned dentists have been aware of this issue for many years. In a 1996 letter to the Journal of the American Dental Association, two dental professors from Tufts wrote:

"An article appeared in the March 1996 issue of Environmental Health Prospectives entitled 'Estrogenicity of resin based composites and sealants in dentistry' that raises some familiar concerns that critics of the profession have espoused. The thesis elaborated in this article states that the bisphenol-A and bisphenol-A dimethacrylaic components of sealant and resins are estrogenic and probably contribute to xenoestrogen exposure in humans.

"As dental professionals who have seen dentistry criticized for the use of mercury in restoratives and the lack of appropriate disinfection procedures for our instruments and equipment, we feel that this issue should be resolved through competent scientific investigation. Hopefully, this issue will be addressed in a more intellectual and scientific manner than the emotion and hysteria that have been the center of some issues in dentistry in the recent past."

Some 13 years later, we still don't have conclusive scientific results about BPA's safety. Consumers and dental professionals alike need a clearer scientific picture. But at the same time, no one needs mass hysteria that keeps patients from getting the dental restorations they need. While the health risks of BPA exposure might not be clear, the risks of tooth decay and abscessed teeth certainly are.

The chemical bisphenol-A (BPA) made headlines last year as a possible health risk – and now it's back in the news.

Will this call the safety of modern dental products into question?

Unfortunately, evidence indicates that BPA can leach from plastics and be absorbed by the human body. It mimics the effects of the female hormone estrogen, and animal studies have linked high levels of BPA with all sorts of unpleasant health problems.

Baby bottles seem to be the most worrisome product, releasing even higher levels of BPA when heated or filled with hot liquid. [Note: Not all baby bottles contain bisphenol-A.] And BPA's hormone-like effects are likely to be even more harmful to a developing baby than a full-grown adult.

Last year, the FDA declared that the amount of BPA released by consumer products is too low to cause health problems. In a June 2008 statement to the US House of Representatives, the FDA's Associate Commissioner for Science, Dr. Norris Alderson, said:

At this time, FDA is not recommending that consumers discontinue using food contact materials that contain BPA. Although our review of the NTP reports is continuing, a large body of available evidence indicates that food contact materials containing BPA currently on the market are safe, and that exposure levels to BPA from these materials, including exposure to infants and children, are below those that may cause health effects…

FDA's reassessment of possible "low-dose" effects of BPA concluded that the current level of exposure to adults and infants is safe as defined in 21 CFR §170.3(i).

However, the FDA is now reviewing that decision. In fact, a recent Harvard University study found elevated levels of BPA in students' urine after only one week of drinking from plastic containers.

Many cities and states are considering banning the additive in some products, particularly baby bottles.

• Canada banned the import and sale of baby bottles containing BPA
• New York's Suffolk County passed a BPA ban
• Minnesota has banned BPA-containing plastic beverage containers for children under 3 (effective for manufacturers January 2010; for retailers January 2011)
• Chicago just passed a city-wide ban on selling baby bottles and children's sippy cups that contain BPA (effective January 2011)
• Connecticut's House will ban BPA from plastic containers used by babies and children (effective October 2011)
• California's Senate narrowly approved a bill banning BPA that still needs to be approved by the state Assembly
• There's more and more talk of a nationwide ban

A number of companies are voluntarily removing or limiting BPA. Water-bottle manufacturer Nalgene has announced it will remove BPA from its products. Both Walmart and Kids-R-Us will stop selling baby bottles that contain BPA. The six largest baby bottle manufacturers will remove the ingredient. Even Sunoco has said that it will not supply manufacturers with BPA if the resulting products are intended for children under 3.

Next week we'll take a look at how this may apply to dental composites and sealants.

Read more:

Bisphenol-A in Dental Composite Worries Dentists

Related Posts:

• BPA Safety in Dental Sealants Worries Some Dentists (video)
• Bisphenol-A in Dental Composite Worries Dentists
• The Chemicals That Worry Dentists (video)
• Dentists Worry About Lead and Mercury (VIDEO)
• Dental Sealant Worries over Plastic Chemical Bisphenol-A

]]> http://www.thewealthydentist.com/blog/572/dental-composite-safety/feed/ 1 http://www.thewealthydentist.com/blog/309/dental-public-health-threats/ http://www.thewealthydentist.com/blog/309/dental-public-health-threats/#comments Wed, 04 Jun 2008 08:00:02 +0000 Julie Frey http://www.thewealthydentist.com/blog/?p=309 Other Dental Health Concerns Include Mercury and Bisphenol-A

In this survey, we asked dentists how concerned they are about various potential public health threats linked to dentistry. Dentists’ concerns, in order, are:

1. Lead in dental lab work
2. Mercury in amalgam
3. Bisphenol-A in composite, and
4. Fluoride in water supplies.

General dentists had higher levels of concern on all issues than specialists. However, specialists and generalists agreed on the relative dangers of the chemicals covered in this survey.

Dentists’ thoughts

• “I’d like to be doing all gold restorations.” (New Jersey dentist)
• “All four of these need to be totally nailed down as to their safety, or lack thereof.” (Arkansas dentist)
• “Two things that will bite dentistry in the butt are fluoride and amalgam if we don’t stop forcing them on the public.” (Idaho dentist)

Mercury

• “150 years have not proved Amalgam to be dangerous.” (Arkansas dentist)
• “Amalgams have saved billions of teeth!” (Washington dentist)
• “A known toxin, no safe levels, should be banned.” (Louisiana dentist)

Lead

• “Lead in dental casting alloy? Outrageous!” (Colorado dentist)
• “Recent articles have debunked the worry over the amount of lead in ‘farmed-out’ crowns. Still, we need to monitor that work.” (California dentist)

Bisphenol-A (BPA)

• “This stuff is everywhere. Composites without BPA just don’t hold up well.” (Wisconsin dentist)
• “It’s probably not too dangerous, but don’t cast stones, Mr. Composite: you live in a glass house!” (New Jersey dentist)
• “It’s ironic that many patients are removing long tested amalgam and replacing them with bisphenol composites of unproven safety.” (California dentist)

Fluoride

• “It’s been shown to be effective, but we shouldn’t be medicating the whole population.” (Colorado dentist)
• “The best public health measure ever instituted in this country for caries prevention.” (Texas dentist)
• “Known to be toxic.” (California dentist)

Post your thoughts or read the complete dental public health threats survey results

Given the recent negative publicity surrounding bisphenol-A (BPA), our survey covered dental sealants and composite. One in four dentists is very worried about the safety of these products.

“It doesn’t matter if composites and sealants are safe,” wrote one respondent. “If public perception is that they are not, it is very harmful to dentistry.”

Here are some additional dentist comments on the subject:

• “The enormous and unexplained increase in the incidence of breast cancer corresponds with the advent of the bisphenol-A introduction into dentistry.” (Michigan dentist)
• “The cumulative release of BPA from composites appears to be minimal from the available research.” (New Hampshire dentist)
• “I had fellow church members ask me if they needed to get all their composites removed.” (New York dentist)
• “I am concerned that we are using a material whose biocompatibility is really unknown.” (New York dentist)
• “I am particularly concerned about using composites and sealants in children.” (Texas dentist)
• “Slow news day?” (Georgia dentist)
• “Forget about bisphenol-A. Resins are far more toxic on a cellular level than amalgam. Are you familiar to amalgam studies showing how cells in a petri dish respond to amalgam? They continue to happily divide. When unset resin is placed the cells die!” (General dentist)
• “A vegan grilled me the other day. I told him that he was at greater risk from salmonella from not washing his veggies properly!” (Colorado dentist)
• “I’m more worried about BPA in soda and water bottles. Patients have never expressed any concern.” (Arizona dentist)
• “Most patients assume that if we are doing something it is okay.” (New York dentist)
• “It’s the amalgam issue all over again. What are all the ‘Bondadontists’ going to tell their patients now?” (Virginia dentist)

Post your own comments or read the complete bisphenol-A and dental composite survey results…

Perhaps you’ve heard the recent news reports of possible health problems with water bottles and other plastic products.

The chemical causing so much concern is bisphenol A, found in some (but not all) plastics. Research suggests that BPA may act like the female hormone estrogen. While hormonal effects have been seen in animal tests, no one has shown the same response in humans.

However, many health experts urge caution, especially with substances that mimic the effect of hormones. Estrogen is a reproductive hormone with feminizing effects, one that has a dramatic impact on sexual development. Some wonder if BPA may be the reason why girls are hitting puberty so early these days. Others fear that a pregnant woman’s exposure to BPA can damage not just the child growing inside her, but that its effect on the fetus’s gonads could harm her grandchildren as well.

BPA exposure is hard to avoid. The chemical may leach into food from plastic containers (especially when heated). In fact, manufacturers of baby bottles now offer BPA-free bottles.

Though plastic bottles have received the most mainstream attention, dentists need to know about another possible avenue for BPA exposure: dental composites and sealants. The dental sealant bisphenol A dimethylacylate is of particular concern.

Dental composites are created from monomers. Composite resin is often based on bisphenol A glycidyl methacrylate (bis-GMA, also known as Bowen’s monomer). Though bis-GMA and some other monomers are chemical derivatives of BPA, BPA itself is not used in dental composites or sealants.

A 1996 study by Nicolas Olea of Spain’s University of Granada was the first to report detectable levels of BPA in the saliva of patients who had just been given dental sealants. The study is still a source of controversy. Further research suggests that some (but not all) dental sealants do raise a patient’s salivary level of BPA. However, blood levels of BPA do not detectably change, and saliva levels quickly return to normal.

This is the dilemma: Yes, there can be detectable levels of BPA. But are they significant?

• Some people will tell you that the EPA says it’s okay and the levels of BPA found in humans are far below the levels found to cause problems in animals.
• Others will say that the levels of BPA found in humans are well above the levels found to cause detectable hormonal changes in animals.
• Some will tell you that dental products cause negligible BPA exposure when compared to food products, water bottles, environmental pollution, and other sources.
• Others will say it’s downright irresponsible for dentists to give young children dental sealants that could damage their reproductive development.
• I will straightforwardly tell you that I have no idea if any of this is a big deal or not.

Here are some other resources…

• Definitely pro-BPA: Bisphenol-A.org
• Somewhat pro-BPA: ADA Statement on BPA
• Somewhat anti-BPA: Wikipedia – Bisphenol-A
• Definitely anti-BPA: Environmental Health News

I’d like to know what you dentists think! Do you have any concerns about BPA in dental composites and sealants? Have your patients expressed any concerns? (If they haven’t yet, expect them to soon, as the BPA issue gets more press.)

Post your thoughts on bisphenol-A