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April 20, 2009 | Web Exclusive

Healthy planet, healthier patients?

 
The potential impact of Bisphenol-A on your patients.

by Dr. Marc Herman

Some dentists have very “green” offices. They recycle, they’re energy efficient and they make eco-friendly purchases, but many may also be using compounds that are potentially harmful. Bisphenol-A (BPA) is an ingredient used in chemical compounds that line the inside of many products and serves as a major component in polycarbonate plastics. It is most often found in baby bottles, sports bottles and food containers.

Associated with adverse health effects such as cancer and heart disease, once ingested, BPA can interrupt proper hormone functioning, alter genes and obstruct development. What, you may be asking, is the dental connection?

Consider composites

Dr. Rafael Bowen introduced the first effective resin-based dental composite in the 1960s. Composites are materials consisting of an organic resin matrix, reinforcing inorganic filler and a silane-coupling agent. Other monomers found in composite resins include: Bisphenol-A dimethacrylate (bis-DMA), ethylene glycol dimethacrylate (EGDMA) and triethylene glycol methacrylate (TEGDMA). Composites without the filler and coupling agent are used as sealants, “sealing out” decay by covering the pits and fissures of a tooth.

Since its inception, we have witnessed the development of macrofill, midfill, microfill, mid-hybrid, flowable and mini-hybrid composites. Many of these composite dental fillings contain BPA as well as bis-GMA or bis-DMA, which can hydrolyze to form BPA.

Look at the literature

In 1996, Nicolas Olea of the University of Granada in Spain, reported detectable levels of BPA in the saliva of patients treated with dental sealants. BPA was found ranging from 3.3 to 30 ppm.

In 1999, Arenholt-Bindslev found BPA ranging from .3 to 2.8 ppm immediately after placement of sealants; no BPA was found at one hour or 24 hour intervals.
In 2000, Fung found BPA in saliva samples one and three hours after application. The range of BPA was 5.8 to 105.6 ppb; no BPA was found after 24 hours post application.

A study published in the Journal of the American Dental Association (JADA) in 2006 found that some dental products leach BPA and could result in low-dose exposures within the range in which health effects have been seen. In a busy cosmetic practice, dentists and dental team members placing composite restorations all day may be exposed to hazardous materials.

It is important to note that the ADA tested the blood of dentists who had dental sealants on their teeth and those who did not. BPA was not found in any of the blood samples from either group, suggesting that if BPA is leached from dental sealants, it is not detectable in blood tests. The ADA stance on the issue is that BPA does not present a hazard in sealants or composites.

Alternative options

One company that has developed a material without BPA is Heraeus-Kulzer. Venus Diamond is a BPA-free nano-hybrid composite material for anterior and posterior teeth. It is available in 23 shades and features low shrinkage and advanced mechanical properties. A revised matrix and filler system allow for optimal strength and low shrinkage stress. Unlike the chemical composition of some competitors reliant on bis-GMA, Venus Diamond is a proprietary non bis-GMA. It meets the criteria for esthetics as well, providing optimum filler density, high wear resistance, color adaptation, ease of polish and an enduring shine.

Conclusion

BPA may leach from dental products after placement, however, in studies no BPA has been found in blood samples, indicating there may be no systemic risk. However, if we have materials that are BPA-free, it may be a smarter, less risky approach to take advantage of those products.

 
"Product Watch: Green Products"

About the author

Dr. Marc Herman is an Attending at North Shore University Hospital in Manhasset, New York. He is Chief of the Division of Practice Administration, Chief of the Division of Craniomandibular Disorders, and Chief of the Division of General Dentistry. He is an active member of The American Academy of Dental Practice Administration, where he served as President from 2001-2002; currently, he serves as Treasurer. He is a member of The American College of Dentists, The Academy of General Dentistry and the American Academy of Dental Sleep Medicine. He receives no remuneration from Heraeus-Kulzer.

Photo: George Doyle / Getty Images