Drinking Soda or Pop: Bad for Teeth or Not?


Hi, I’m Dr. Rob Karlinsey, an oral health resource for clinicians, researchers, and laypeople alike. When I give presentations about preventive dentistry, which usually involves fluoride and remineralization, I’m often asked several questions. Because I’m finding that some of these questions are frequently asked and are relevant to today, I thought I’d prepare and share with you several unscripted Q&A videos regarding my opinions.

So here’s a question regarding carbonated beverages:

  1. Question: Although dentists and reports claim carbonated beverages (like Coke or Pepsi) is bad for the teeth, I know people who have drank soda all their life without having cavities. So what’s the deal? Is it just a scare tactic, or is there something else? What’s your opinion?
  2. Answer: To answer this question, we need to familiarize ourselves with both low pH and acids, as both of these lead to demineralization, or loss of mineral, from tooth structure.
    1. The loss of tooth mineral is usually accomplished by acids. Typically, we are told to watch the sweets and other ‘fermentable’ carbohydrates (including potato chips and crackers), as these are essentially feedstock that certain bacteria convert to acids. In turn, these acids will gradually dissolve tooth structure.
    2. But such demineralization also occurs without the microbial middle-man: this is known as dental erosion, and involves the gradual loss of tooth structure. This isn’t a ‘cavity’ but actual erosion of tooth mineral.
    3. But, whether it’s caries or erosion, both require a low pH environment, and certain types of acids. And, importantly, the combination of both processes can work in concert with one another. So, for instance, enjoying apple juice and crackers can make for a potentially dental damaging situation.
    4. First of all, loss of tooth mineral begins anywhere between a pH of 5 and 5.5. Our teeth are mostly comprised of apatite (actually, it’s carbonate apatite), and this is the approximate range in which the apatite mineral can dissolve.
    5. Thus, then the pH falls below 5, demineralization can occur:
      1. With respect to the formation of cavities, usually, this drop in pH resides in the plaque/biofilm contacting the affecting tooth surfaces
      2. But with respect to dental erosion, this can be achieved directly from the foodstuff or beverage
    6. Because most flavored beverages usually are acidic, this means, the pH is usually less than 5
      1. In general, most things sour will qualify as being acidic. Think most things citrus-flavored, including oranges, limes, lemons, along with tart or sour candies
      2. Within this broad group are most carbonated beverages, most sports drinks, most juices and juice drinks, many teas (especially herbal) and flavored waters, and alcoholic beverages such as margaritas and wine.
        1. Thus, this applies to beverages such as Sprite, Coke, Pepsi, Gatorade, Powerade, many herbal teas, and such
    7. Next, the type of acid in the food or drink matters considerably, as each type of acid interacts differently with the minerals of the tooth
      1. The most damaging acids commonly found in foods and beverages include phosphoric acid and citric acid
        1. Citric acid is found in most juices, carbonated beverages (like Sprite), sports drinks, flavored waters and candies. Citric acid can be very harmful to teeth due to its pH. In fact, citric acid is sometimes used to remove mineral aggregate in root canal procedures.
        2. Phosphoric acid tends to be found in certain carbonated beverages, especially darker colas. In fact, phosphoric acid among the lowest pH values (it’s less than 3) which can render this acid especially risky for the teeth.
      2. Some lesser damaging, but still potential include malic and lactic acid
        1. Lactic acid is commonly found dairy products
        2. Malic acid is commonly found in apples and apple juice
    8. Thus, the combination of both low pH and certain acids, can lead to demineralization of the tooth structure due to caries-like decay, erosive loss, or a combination of these two.
    9. My suggestion is to avoid holding the drink in the mouth or somehow prolonging contact with the teeth (including mashing an orange lobe to the front teeth), and limit rigorous swishing (sometimes athletes do this)
    10. In summary, I support the use of trying to rid the mouth of the acidic nature of the food or drink:
      1. Consuming a calcium-rich food or drink after the acidic food/candy/beverage
      2. Use of a polyol sweetened gum or mint
      3. If polyols are not desired, consider mint-flavored, or at least non-sour, candy/gum/mint options
      4. Rinsing with water or a pH-friendly fluoride mouthrinse
      5. Do NOT brush the teeth afterwards, as this can worsen the mineral loss

Oh, and just a comment about whitening: the use of peroxides isn’t terribly damaging per se compared to phosphoric, citric, lactic or even malic acids. However, if the pH of the whitening systems is less than 5, which it usually is, this can be damaging. So look for whitening systems that contain fluoride, since this can help reduce demineralization risks. Note that the potassium nitrate this added to many whitening systems is only there to deaden the pain from the whitening process, and doesn’t do anything to protect the teeth from demineralization.

2018-03-09T22:18:47+00:002018|Media, Q&A|

Robert L. Karlinsey, PhD

Dr. Robert L. Karlinsey earned a BS in Physics and PhD in Chemical Physics, holds several patents, and has published in multiple fields including dentistry, chemistry, and materials science. His lifelong struggles with his own dental decay ultimately inspired him to investigate the remineralization of teeth.