Xylitol: Is it All Hype, or Is There Something More?


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 regarding xylitol, is at all hype, or is there something more?

  1. First, I want to comment on its efficacy
    1. Really a modest 10% clinical reduction in coronal caries can be achieved with regular use – and this isn’t necessarily statistically significant
    2. Has better effect for root caries: ~ 40% reduction over a 3-year period
    3. Why here? Xylitol can help boost populations of anaerobic gram-positive microbes (e.g., certain types of bacilli and cocci bacteria) are prominent in the tongue, saliva, cheek, gingival margin
    4. For those with a history of tooth decay, and already using fluoride toothpaste, no additional clinical benefits are realized.
  1. Still, it’s better than sugar in that it does not contribute to acid production by fermenting bacteria – therefore, it does not promote tooth decay
  2. Help to repopulate the GI tract
    1. Helps reduce caries-causing microbial activity (e.g., S. mutans)
    2. Helps populate with more ‘benign ‘microbial species
    3. WARNING: There will be associated gastric discomfort
    4. This can last up to a few weeks as the microbial shift is in process
  3. About remineralization
    1. It does not by itself contribute tooth-strengthening minerals.
    2. Provided the salivary gland are working normally, the action of secretion leads to tooth-strengthening.
    3. Of course, the sweetness of xylitol can help saliva secretion: it is, after all, just as sweet as sugar
    4. In a toothpaste?
      1. From a professional perspective, I’m not convinced. I mean, even lozenges, mints and gums can produce marginal benefits, usually any benefit is dependent on the flow of saliva.
      2. Thus, while I’m not going to rule it out, I find it odd that if xylitol toothpaste did work, then surely it would be discussed in the existing body of xylitol knowledge, which spans more than 50 years; however, it isn’t, so I have significant doubts regarding its anti-cavity benefits.
      3. For it truly to show a benefit, it would have to be tested against a ‘gold-standard’ fluoride toothpaste in several clinical trials
    5.  Note that other sugar-alternatives confer benefits, too
      1. Other polyols, including sorbitol, erythritol, stevia and even the synthetic sweetener sucralose do not promote tooth decay
      2. Super-sweet synthetic sugar alternatives (like aspartame and saccharin) do not promote tooth decay
      3. While xylitol is as sweet as sugar, sorbitol is about 60% as sweet as sugar and its effect on S. mutans is not as pronounced as xylitol
      4. Sucralose is much sweeter than sugar, but not really designed to modulate the oral flora
      5. Erythritol, which has one carbon less than xylitol and is therefore a bit smaller, is actually kinds of exciting. Having about 70% sweetness of sugar, emerging evidence indicates it’s even more effective than xylitol.
    1. For efficacy to amount to anything exciting, at least 6 grams must be consumed
      1. This holds for sorbitol, xylitol and erythritol
      2. This may also be challenging since mostly these are found in small comestibles – usually mints, lozenges and gums
      3. Again, the action of salivary stimulation is driving a lot of the benefits, so salivary flow is critically important. If someone has dry-mouth-like effects, the amount of polyol needed to exert any benefits will likely have to be increased
      4. Fortunately, if one prefers baking, there are sorbitol, xylitol and erythritol ingredients that can be used to make the chocolate chip cookie – so try it! Just keep in mind, the gastric discomfort
    1. Importantly, I want to point out that the use of polyols (including xylitol) to change microbial composition is NOT permanent.
      1. So if you switch back to sugar, there will have to be repopulation
    1. Finally, I certainly recommend the use of such polyols as part of a program that can help thwart tooth decay (and probably freshen the breath, too).
      1. However, for best benefits, I would probably use these in the forms of mints, gums, lozenges, and such after and/or between meals.
2018-03-12T14:30:00+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.