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Could a natural sugar be the answer for improving oral health?
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by Trisha E. O'Hehir, RDH, BS Editorial Director, Hygienetown Magazine
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Caries and periodontal diseases are first and foremost bacterial infections. Bacteria accumulate and feast on sugars and fermentable carbohydrates. If the acid produced by Mutans streptococci (MS) demineralizes the enamel at a faster rate than the saliva can remineralize it, caries result.
The volatile sulfur compounds released by the bacteria enhance the permeability of the junctional epithelium, thus allowing toxins and acids produced by the periodontal pathogens to penetrate and trigger the immune response. White blood cells, polymorphonuclear neutrophils (PMNs) are called to the area to defend against the bacteria, but in their travels from blood vessels in healthy connective tissue through the epithelial layer to the bacteria in the sulcus, the PMNs release cytokines that actually destroy healthy connective tissue. If the immune system is weak, the PMNs are working at half power to phagocytise the bacteria, so more PMNs are sent |
to the area, and even more of the healthy connective tissue is destroyed in the process, leading to attachment loss. Preventing caries and periodontal disease targets the bacteria first, then the remineralization of enamel and strengthening of the immune system.
Traditionally, brushing and flossing comprised the foundation of traditional oral hygiene. According to the research first published by Dr. Charles C. Bass and Dr. Levi Spear Parmley, effective mechanical disruption of the bacteria with the toothbrush and dental floss stops the disease process.
Dental hygienists have mastered effective daily oral hygiene themselves, but
the general public needs some help. Researchers have suggested that since the
general public can't or won't effectively disrupt the bacterial biofilm each
day, they need chemicals to destroy the bacteria. Based on this conclusion, drug
and discount store shelves are filled with a wide variety of toothpastes and
mouth rinses to fight the bacteria and acids responsible for caries and periodontal
diseases.
Before we settle for chemicals, let's look at the disease process again and the role of the bacteria. Bacteria plus sugar equals acid that demineralizes the enamel and leads to caries. This same accumulation of bacteria eventually
reaches critical mass, attracts more Gram negative species and sends toxins through the junctional epithelium, triggering periodontal diseases. What if we could reduce the amount of bacterial biofilm from the get go without using chemicals? This would lead to less caries and periodontal disease, despite the lack of optimal brushing and flossing.
What would you think if I told you that bacterial biofilm could be prevented by eating a special sugar? Crazy right? Not really. Xylitol is the sugar that prevents acid production by the bacteria. It makes the bacteria slippery instead of sticky so forming a biofilm or even sticking to tooth surfaces is difficult. Would you and your patients like the recommendation to chew gum or eat candy several times each day to stop dental disease?
Besides stopping dental disease, xylitol sugar is safe for diabetics and the cool fresh taste stimulates saliva, thus soothing dry mouth. If bacterial levels in the mouth are controlled, bad breath is eliminated. Xylitol also reduces otitis media or ear infections and has been shown to enhance bone formation by assisting calcium molecules.
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If xylitol is so great and can do all these things, why isn't it as popular and well known as brushing and flossing?
It is, in countries other than the United States. Finland was the first country to notice the benefits of xylitol and to support national education programs. In 1988, the Finnish Dental Association officially endorsed the use of xylitol. The Swedish Dental Association followed the next year and so did the United Kingdom in 1990. Many other national dental associations have endorsed the use of xylitol, with the exception of the American Dental Association.
What is xylitol? Xylitol is a natural sugar that was first harvested from the bark of birch and beech trees in Finland. Most sugars are six-carbons, which are acid producing and a nutritional source for bacteria. Xylitol is a five-carbon sugar, making it alkaline rather than acidic and not a nutritional source for bacteria. Xylitol is a natural sugar and is produced in small amounts in our bodies every day as part of glucose metabolism. It is currently extracted from corncobs and stalks, but not from the corn itself. It tastes just like sucrose, has fewer calories, and a slight cooling sensation that stimulates salivation.
How do we know it works? Xylitol was first produced in Finland during World War II, when ships could not reach Finland to deliver sugar. The forests of Finland provided an excellent source of tree bark after the trees were harvested for the wood. After the war, sugar was again able to be delivered by ship and xylitol production stopped. Years later, dentists noticed that the children who ate xylitol had stronger teeth than those who now eat sucrose. Sugar scientists hypothesized that the xylitol was a preventive rather than destructive sugar and that long-term benefits were now being observed.
To test this theory, a two-year study was undertaken to measure the effects of replacing all sugar in the diet with xylitol. This was a huge undertaking, since all foods eaten had to be made with xylitol, even things like catsup. Compared to a traditional sugar diet, the xylitol diet did change the oral health. The next step was to determine if xylitol could be added to the diet in frequent small doses rather than completely replacing sugar. Chewing gum was the delivery system first tested and found to be effective. Many other studies have determined the dose and the frequency needed to provide the greatest oral health benefit. Aside from chewing gums, candies, mints and syrups have been tested and found to be effective.
While working at the University of Michigan in the 1970s, Finnish scientist Kauko K. Makinen undertook what is now the classic xylitol
study. The project involved school children in Belize City, in the country of Belize. This 40-month study compared various doses and combinations of xylitol and sorbitol. Findings confirmed that chewing 100 percent xylitol-sweetened gum several times daily reduced the caries rate approximately 70 percent. Combinations of xylitol and sorbitol were not as effective, since sorbitol is a six-carbon sugar and can contribute to acid formation.
What are the current recommendations? Thirty-three years ago the FDA ruled that xylitol was a safe food additive and it's safe in any amount. Based on many studies, (reference list available online at www.xylitol.org) the recommendations for oral bacterial biofilm control are four to 12 grams of xylitol spaced out during the day. With as little as four grams, oral health differences will be seen. The oral benefits reach their maximum at 17 grams per day. More than that will not provide additional oral benefit. Side effects are similar to eating fruit. Eating a lot more fruit than your body is used to might lead to diarrhea. The same is true of xylitol at levels of 20 grams per day. Tolerance can be built up by slowly increasing daily levels to 50 grams per day, if you want to use xylitol to replace all sugar in the diet.
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Finland was the leader in endorsing and supporting the use of xylitol 30 years ago. The United States has been slow in realizing and promoting the benefits of xylitol as a supplement to brushing and flossing. Adding at least five grams of xylitol, five times daily is a good idea for everyone, not just those at risk of caries. It makes sense for anyone who wants to reduce the bacterial biofilm in their mouths and sinuses. We might think of xylitol as something to be added beyond brushing and flossing, but for many populations, starting with xylitol makes sense as the first approach to oral hygiene, followed by brushing and flossing. |
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