Kyle Taylor, DDS

Tranquil Bay Dental

2415 Penny Road Suite 203

High Point, NC 27265


At Deep River Pointe

The Dr. Writes

Sugar and the “Rules”

True or False? Cutting down on my sugar intake will reduce the potential for cavities. (Hint: This question really cannot be answered with a “true” or “false.”) When it comes to dental decay (a.k.a. caries or cavities), it is not always what you drink and eat, but how you drink and eat it that matters.

Consider this very possible hypothetical: One identical twin drinks five canned diet sodas a day and has no cavities year after year (keep in mind we’re not talking about the other possible health effects of this, only dental decay). His twin brother drinks only one diet soda a day, yet has several cavities every six months. How can this be?

The first twin drinks two sodas with each meal other than breakfast over about a 20-minute period, then brushes his teeth afterward. He also has one during the afternoon, but he drinks it fairly quickly (10 minutes maximum) and afterward rinses a couple times well with water. The second twin opens his soda at work in the early afternoon and “nurses” it for about four hours (a sip here, a sip there). No rinsing with water.

You are thinking, “But you said they were diet sodas.” Exactly. While regular sodas are worse, diet sodas also greatly contribute to dental decay. The acid in diet drinks can temporarily open up pores in the enamel, allowing the bacterial plaque that is always on your teeth (even shortly after brushing) to more easily attack. This is biology we’re talking about here. Dentists and hygienists are not here to take away all your fun…just help you understand the biology.

Dental decay is caused by a very specific bacterium that becomes most active against tooth structure when provided with sucrose (sugar), or breakdown products from carbohydrates. The bacterium also thrives with a low or acidic pH. It takes very small and frequent “doses” or sips to “keep the machine running.” A rough figure of 20 minutes of cavity-potential-pH per sip of a high acidic and/or high sugar drink is a rule of thumb. So, length of time—or duration—of acid and/or sugar contact with tooth structure is critical.

Let me guess: Right now, you are probably adding up your daily hours of high-cavity potential with your liquid intake. In order of cavity potential, common problem beverages are: regular sodas, sports drinks, sweet tea, diet sodas, fruit juices (fructose is a sugar), and coffee with sugar. Of course we could list many, many more. Every person with new dental decay needs to review his own situation for potential cavity-causers.

So you say, “I am willing to shorten frequency and the length of time I drink these, but what are some alternatives to these types of drinks?” Here is the best alternative: Water, of course, tap or bottled. (But keep in mind children 12 years old and under need the fluoride that often only comes from city tap water and is not present in bottled water). Tea or coffee, with or without artificial sweeteners, seems to be acid-neutral, but lemon in the tea could alter it toward the acidic side. Also, you will notice more staining of your teeth in a short time if you sip coffee or tea over long periods each day. [Side note: Since artificial sweeteners have their own database of questioned health and side effects, and not everyone can consume them, please consult your physician or your child’s pediatrician before changing your liquid or solid diet to include them].

And, of course, you could use a straw, and much of the sugary, acidic liquid will bypass your teeth. This will also help with iced tea also, with regard to reducing stain buildup.

“You are talking about what I drink a lot. What about what I eat?”

Cake and candy bars can certainly contribute to tooth decay, but consider the frequency factor: Filling foods are not as critical if you actually get full and quit eating. If you nurse your candy bars for hours, like some folks nurse their sodas, then you may have a problem. Tiny soft or chewable candies that can be popped in, one after another, hour after hour, can be a real concern, as can candies—or even non-candies like raisins—that stick in your teeth. For those of you who like to open a bag of chips and watch a two-hour movie: Chips contain carbohydrates that are converted to sugar in your mouth. Except for on Halloween, having enamel like the pirates in the Pirates of the Caribbean movies is not cool.

In my experience, there are two groups of patients with occupational hazards with regard to dental decay: Those who cook or serve food and sample small tastes throughout the day; and long-distance drivers, many of whom eat often, and eat carbohydrate or sugar-laden snacks, perhaps in order to stay awake. These are all examples of ways to consume solid foods, and types of solid foods that contribute to a high potential for tooth decay.

“Is chewing gum bad?” Not if it is sugarless, and if it is, you may even somewhat reduce your cavity potential, studies have shown (Google Xylitol, Erythritol, and Sugar Alcohols). Breath mints, cough drops, hard candies, etc.? Make them sugarless, or you might have a problem. And while I am informing, not lecturing (remember dentists did not make up “The Rules”), please avoid chewing up that peppermint candy to get it down faster…unless you are a fan of dental crowns.

“What about artificially sweetened powered drinks (Crystal Light®, Wyler’s®, etc.) and flavored waters?” Many of the artificially sweetened powdered drinks are not acid-neutral, and the common addition of citric acid definitely makes them on the acidic side. Proceed with caution. New flavored waters are appearing every day, so check the contents for sugar or hints of acid-producing ingredients.

An important side note about rinsing versus brushing: If your acid tooth bath (a.k.a. soda or juice or sports drink) was consumed without food, then the best thing to do is to rinse only—not brush—for at least 20-30 minutes. This is because the acid can temporarily weaken the enamel, and in this state you can actually brush off micro-layers of enamel over time. Waiting allows the enamel to “remineralize” or strengthen itself back.

The source of the decay may not be obvious. I often ask pregnant females whether they awake in the middle of the night to take antacids for their stomach. Many do, and most have not thought to look near the bottom shelf in the stores where they sell the (less marketable, I guess they think) sugarless antacids. But be aware that the label must say “sugarless,” and these are getting harder and harder to find. I have recently noticed that many stores have started making these tablets that contain both an artificial sweetener plus an outright natural sugar, dextrose (which converts to glucose). Since brushing at 3:00 a.m. does not occur to most folks, the sugarless option keeps the antacid from causing any harm, even though about ten percent of it seems to stay in the grooves of your teeth for the next several hours.

There have been a couple of patients through the years with self-described “excellent diets” that could not fathom what was causing their cavities, especially since both were very tuned in with their health and their nutrition. With the first, we went through my entire cavity “gotcha” list. Nothing. Then she returned another day for some restorations (fillings), and she said “Dried fruit. I snack on dried fruit all day.” “Ah ha!” I thought.

The second one was a marathon runner who was quite flustered at the thought of having so many cavities, because being a fine-tuned athlete, she always ate “super healthy” foods. After some discussion she let it come out that she was a “grazer”—she does not have big meals but is eating various morsels throughout much of the day. “Ah ha!” I thought. “Hmm,” I said, “So much of the day you’re popping in things like grapes, strawberries and various other foods that contain natural sugars and carbohydrates, right?” There was silence until she said “Well, I’m not going to stop!” Luckily, there was not a “stop order” in store for her, but just my suggestion of some modifications: Try to condense the grazing to more limited periods of time, rinse often with water while you are grazing, and go on a prescription fluoride dental toothpaste for night time use that will protect your teeth with over 4.5 times the amount of fluoride that’s in most over-the-counter toothpastes. She seemed accepting of these suggestions so I assume she “ran” with it.

Sometimes you have to be your own sugar sleuth, so start looking at nutritional labels from a dental standpoint as well. Remember that acids matter as much as sugars, and that many foods (carbs) are converted to sugars in the mouth. Fruits are great, but fructose is still a sugar. Sports drinks, flavored waters, even diet sodas mater. Moderate your consumption in amount and duration, and please use water to Rinse Often.

Written by Kyle W. Taylor, DDS