Comment submitted by Jerome Bowman, Public Affairs Counsel, American Dental Associaton (ADA)

The American Dental Association (ADA) is pleased to offer these comments on Environmental Protection Agency’s (EPA’s) Proposed Study of Unused Pharmaceuticals from Medical and Veterinary Facilities. The ADA is the largest dental professional association, representing over 155,000 dentists in the United States, including 71.8% of the active dentists. The proposed data collection effort by EPA is not directed at dental offices. As a result, the ADA is not offering comments specific to the research instrument itself. Rather, the ADA comments merely to explain why the decision to omit dental offices from the data collection effort reflects the most sensible approach to the project. Dentists, unlike many physicians, typically do not dispense pharmaceuticals in the office. (For purposes of these comments, “pharmaceuticals” do not include local anesthetics. These are discussed separately below.) While it is, of course, common for dentists to prescribe pharmaceuticals to their patients, dentists seldom act as pharmacists. Instead, they provide their patients with a written prescription which the patient then fills at his or her local pharmacy. This conclusion is bolstered by data developed by the ADA. Dentists simply are not purchasing pharmaceuticals in any significant quantity. The ADA survey of dental practices for 2006 (“The Survey of Dental Practice 2006”) reported that 'drugs' accounted for only 0.4% of a solo practitioner's expenses; which translated to a median expense of $500.00. The most commonly used pharmaceutical agents in dental offices are injectable local anesthetics. (These are not included in the data from the 2006 survey reported above.) It is not clear that these drugs are relevant to EPA’s study. In the event they are, ADA is providing information on anesthetic use in dental offices. The most commonly used drugs are the "amide" type anesthetics. The first drug developed in this group is lidocaine (Xylocaine) which has been the most commonly used anesthetic in dental practice for at least 40 years in the US. An "ester" type anesthetic, procaine (Novocain), was the standard in the early to middle of the last century but it has not been available in dental cartridges (the typical delivery means used by dentists) for many years. One reason for this shift may be that many people develop allergies to this type of chemical structure but that almost never happens (some say it has never been documented to happen) with lidocaine and related drugs. Several other local anesthetics related to lidocaine are also used for in dentistry (mepivacaine, bupivacaine and prilocaine mainly, although others are available but not in dental cartridges). Another anesthetic now commonly used in the U.S. is articaine (Septocaine). There are other brands of articaine available outside of the U.S. and this is the most commonly-used dental anesthetic in Germany, France and some other countries in Europe and elsewhere. Articaine has both amide and ester linkages in its structure and there are other chemical differences compared to lidocaine. Regardless of the drug used, local anesthetics for dental use are supplied in single-use glass cartridges containing approximately 2 ml of solution. Disposable syringes are available but the vast majority of cartridges are used with stainless steel dental syringes. A disposable dental needle is attached to the syringe for delivery of the drug. After injection, the spent cartridge is often disposed of via the medical waste sharps container. This is because, before and during the injection, aspiration is used to confirm that local anesthetic is not introduced into a blood vessel. The cartridge may contain blood as a result of this process. However, if the cartridge is not disposed of in this way, the remaining anesthetic is retained in the cartridge. Because of this, it is very unlikely that this waste anesthetic would be emptied into a sink or otherwise enter the plumbing system. To summarize, dentists seldom dispense pharmaceuticals in the office. Both experience from dentists and the ADA data cited above confirms this. The primary exceptions to dispensing pharmaceuticals in the office are injectable anesthetics. It is not clear if this is a focus of EPA’s data collection efforts. Nevertheless, as discussed above, these materials are typically disposed of with medical waste or with other solid waste, rather than through the office’s plumbing system. For all of these reasons, the ADA supports the decision of EPA to exclude dental offices from this data collection effort. Please contact Jerome Bowman, Public Affairs Counsel, ADA, with any questions or requests for additional information. Mr. Bowman may be reached at bowmanj@ada.org or at 312-440-2877.