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Why Does One Dentist Give Different Advice Than Another?

I recently had a question from a patient about the advisability of the use of Listerine mouthwash because I had told her one thing, and another dentist had told her something else. Let’s use this question as an example of the pro’s and cons of a particular product.

There has been research over the decades on Listerine. In fact, Listerine was first used as a surgical antiseptic in the 1860’s. It took several decades for people to start using it in the mouth. By 1914, it was marketed as a mouthwash. Later, it received ADA (American Dental Association), and later CDA (Canadian Dental Association) approval. This approval process is a long and expensive ordeal because the company seeking approval has to prove through scientific studies designed in a very strict way that their products actually do what their labeling says they do. Listerine says it fights plaque and gingivitis. Many studies over the years have proved that those claims are indeed true. Listerine packaging used to say it was as effective as floss. The ADA approval process actually found that in the narrowest of terms, it is. However, a court in the States basically found in 2005 that the narrowness of the claim’s conditions was misleading to the public so the claim was ordered to be removed from the packaging.

The product has 27% alcohol as one of its ingredients. Researchers differ on exactly what it is about Listerine that reduces bacteria in the mouth enough to clinically notice a difference in the health of the gums. There are four ingredients that are listed as the active ingredients (meaning the ingredients that actually are producing the listed health benefits) of Listerine. Some researchers say they believe it might actually be the alcohol that does the killing of the bacteria. There are no studies that have tested the four other ingredients listed as active ingredients without 27% alcohol mixed with them. So what is the bottom line on this? Listerine does what the bottle says it does: Kills germs that cause gingivitis, plaque, and bad breath. If you buy the tartar control type, it also makes it take longer to form tartar. Other products that contain some of the ingredients that are found in Listerine may have the same effect, but they may not. There is not substantial research to prove either point of view. Additionally, to be assured of the listed benefits (that have been verified by the ADA and CDA—not the government), you must follow the directions listed on the bottle.

Of course, as with all medications, there are negative effects (also called side effects). One of them is an alleged increase in risk of mouth and throat cancer. This risk is not agreed upon by the experts. What does that mean? It means that the studies that showed the effect (increased incidence of mouth and throat cancer) were not designed or completed in a way that was entirely convincing to those who understand the subject best. This is the way of science. It is sort of a two steps forward and one step back cautious approach. And this differing point of view is dizzying for many patients and health care practitioners alike. However, your dentist is specifically trained to look at scientific research with a critical eye, sifting what is valuable and reliable from what is not. Clinical experience, consultation with colleagues, and training are critical in this information sifting process.

Some products or procedures have stood the test of time, and some are new. The older procedures or products that are regarded by the profession as effective and have been proven by scientific research to be effective are viewed as standards by which the newcomers are judged. A new product is not better just because it is new. It must be compared by the experts to the existing standards and scrutinized carefully through a very reproducible and transparent scientific process to decide whether a change is justified. Even when a new product or procedure is decided by some of the experts to be better than the tried and true item or method, the comparison through scientific studies goes on for years, or as in the case of Listerine, decades. In the field of antiseptic mouthwashes, Listerine is the tried and true standard by which all the newcomers are judged.

Much information can be accessed on the internet about procedures and products. Your dentist is on your side to minimize damage from normal “wear and tear” and maximize prevention of disease in your mouth. It is good to be informed. Make sure to include your dentist in your search for what will be the best approach in your individual case to prevent dental problems and to treat problems most effectively when they arise.

- This article was written by Dr. Mike Christensen and published in the Daily Miner and News, and Enterprise. Local Kenora News Publicatons (1998-2006)

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