How does xylitol work?

- Research has shown that xylitol helps to prevent tooth decay in a couple of different ways. Most methods have to do with the inability of decay-causing bacteria to use it as a food source.



The first dental research to investigate the use of xylitol in preventing cavities was performed in Finland (the "Turku Sugar Studies," published in 1975). Since that time, a number of additional studies have been performed, throughout the world.

Burt (2006) reviewed this accumulation of data as a part of his work for the paper "The use of sorbitol- and xylitol-sweetened chewing gum in caries control." (Published in the Journal of the American Dental Association.)

Included in this publication was a tabulation of the various dental-health benefits that different studies had attributed to xylitol. We've outlined them below, and with each have provided an explanation of the science associated with them.

As background for this information, you may find reading our page "How cavities form" helpful.

Xylitol sugar.

Xylitol can be used in conjunction with fluoride to prevent cavities.

Note: Xylitol is a true preventive.

It's important to note that Xylitol is special because it actually helps to prevent the conditions that allow cavities to form.

That's in comparison to fluoride whose anti-cavity mechanism is one of assisting in the repair of tooth enamel that has already been damaged.

This difference doesn't imply that one is better than the other. Both approaches are very valuable and both should be taken advantage of.

How xylitol prevents cavities -

The rest of this page describes the many ways xylitol creates its anti-cavity effect.

Note: Each of these mechanisms takes place solely due to the presence of the xylitol inside your mouth. That means you don't have to swallow it for it to be effective. Doing so does not create an added systemic effect.
For this discussion, you'll need to know these terms: 1) Cavities are caused by cariogenic bacteria. 2) Tooth demineralization = Cavity formation.

1) Some types of cariogenic bacteria can't digest xylitol.

The inability of some types of decay-causing bacteria to use xylitol as a food source is beneficial in several ways.

a) Tooth demineralization is prevented.

Demineralization takes place when a tooth's surface is exposed to the acidic waste byproducts created by cariogenic bacteria as they consume (digest) sugars.

Since some strains of these kinds of bacteria can't metabolize the sugar xylitol, when it's available to them as a food source less acid production will occur. This in turn means that the acidic conditions needed for tooth demineralization will be less likely to exist.

b) A less-than-ideal living environment tends to exist.

Colonies of cariogenic bacteria do best when living in an acidic environment.

Since these kinds of bacteria have trouble metabolizing the xylitol molecule, when this sugar is given to them as a food source they produce a lower level of acidic waste byproducts. And that means that the dental plaque environment in which they live will be less favorable for their growth.


c) The starvation effect.

Xylitol molecules in a person's mouth helps to starve the cariogenic bacteria that live there because they try to but can't use it as a food source.

Since the bacteria are malnourished, their population as a whole will not thrive and grow. And due to these reduced numbers, less acidic waste products will be created and thus it will be less likely that the acidic conditions needed for cavity formation will exist.

d) Population changes.

Long-term xylitol exposure will ultimately influence which types of cariogenic bacteria are the dominant ones living in a person's mouth.

When it's present, the growth of xylitol-sensitive" strains (types of bacteria that cannot use it as a food source) will be suppressed. In comparison, the number of resistant bacteria (those types that can tolerate it) will, over time, predominate.

Because xylitol-resistant bacteria are less capable of causing tooth damage than their more virulent counterparts, this population shift makes it harder for cavities to form.


2) Xylitol causes changes in dental plaque.

a) Less dental plaque.

As mentioned previously, the inability of some types of cariogenic bacteria to metabolize xylitol will cause a reduction in their numbers. And this in turn will tend to reduce the total amount of dental plaque that forms.

This can be due to both the Starvation-effect and Less-than-ideal-living-environment phenomenons described above.

b) Less adherent plaque.

With long-term xylitol exposure the predominant types of cariogenic bacteria that live in dental plaque will tend to shift from xylitol-sensitive to xylitol-resistant strains.

Research suggests that the "resistant" types are less capable of adhering to, and therefore colonizing, tooth surfaces. (Bacterial colonies being able to adhere to teeth is an important step in cavity formation.)

3) Xylitol use promotes tooth remineralization.

Remineralization is a process that helps to reverse the damage caused by demineralization (the process that results in tooth decay). Two different mechanisms may be responsible for how xylitol is able to promote this kind of tooth repair.

a) Less acidic plaque.

Demineralization takes place when dental plaque creates an environment on a tooth's surface that is predominately acidic (pH 5.5 and below). During those times when less acidic conditions exist, tooth remineralization has the potential to take place.

With xylitol use, the pH of dental plaque tends to remain relatively less acidic (see above). As a result, it's more likely that conditions will exist where tooth remineralization can occur more frequently, even to the point of being the predominantly occurring process.

b) Molecular-level effects.

The xylitol molecule itself may help to promote tooth remineralization.

Studies have demonstrated that samples of demineralized tooth enamel immersed in a solution that provides a suitable environment for remineralization and also includes 20% xylitol show a greater degree of repair (especially in the middle and deep layers of enamel) than equivalent solutions that didn't. This evidence suggests that xylitol assists in the movement of calcium ions.


Input from site visitors.

Howdy! This post could not be

Howdy! This post could not be written any better! Reading this post reminds me of my previous room mate! He always kept talking about this. I will forward this post to him. Pretty sure he will have a good read. Thanks for sharing!

Thank you for posting.

Thank you for posting.

Xylitol treatments instead of fluoride treatments

Is there any research to formulate a compound using a xylitol dental aplication to treat tooth demineralization just below the gum line caused by oral disease.
Fluoride treatments are toxic to our bodies.

Thanks for posting Donna,

If you're trying to avoid fluoride, ACP (amorphous calcium phosphate) is a compound that's used to promote tooth remineralization.

We Googled the words "ACP xylitol" and saw products available. Although at first glance we didn't see it clearly stated what amount of xylitol they contained. (Dosing within an appropriate range is an important factor with xylitol use.)

Possibly a better plan would be to use a known high-quality xylitol product (see our pages) and separately an ACP product specifically targeting tooth remineralization (some of the best ones require an Rx from your dentist).

And to anyone reading, the comment the poster makes about fluoride is their opinion. This website supports the use of fluoride and considers using it in conjunction with xylitol to make a good choice. It's a way of using two entirely different mechanisms to fight the the battle against tooth decay.

Per cent Concentration of Xylitol on toothpaste

Does anyone know if the concentration makes any difference? I use a water flosser followed by fluoride toothpaste for sensitive teeth. Lately I started dipping the toothbrush with toothpaste into a little pile of xylitol. This coats the toothpaste with xylitol and tastes fine and feels clean.
Does anyone know if the concentration of xylitol makes any difference?

By the way, I don't rinse

By the way, I don't rinse after brushing so that good stuff sticks around for awhile.

This website and the links are awesome! Thank you so much!


Yes concentration matters, in the sense that your total cumulative oral exposure to xylitol needs to meet a minimum daily quantity for it's effect on oral bacteria to take place.

Whatever amount you choose to use at brushing time should simply be added to your total of other daily xylitol exposures. If it's just minimal, then it should be counted as such.

And yes, the "not rinsing afterwards" is a good habit to practice. Doing so provides a longer exposure of the xylitol to the bacteria.

Well done

Very well written and informative. Thanks for posting it.


Wow. I never knew how helpful xylitol can be. Thanks for giving me something to chew on!!!

That's funny, well said.

That's funny, well said.

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