through my teeth

A summary of some personal research on oral health.

Over the past ten years I have repeatedly had problems with caries and inflamed gums. My dentists always gave general advise on dental care and filled carious lesions with a steady hand. I became very good at following the recommended hygiene procedures, yet the problems persisted. Though my issues are not particularly serious and in no way uncommon to our times, I decided that if I wanted long-term improvements to my dental health, I would need to understand the contributing factors for myself.

I am making this website to share a summary of my research and conclusions.

Some basic information about oral health as a question of ecology

  1. Your mouth is home to a wide range of microorganisms.
  2. The name for your mouth as an environment and all of the microorganisms inside of it is microbiome.
  3. Everbody has a slightly different microbiome. Your microbiome depends on your physical features, your personal history and your lifestyle habits.
  4. Some microorganisms are advantageous or harmless to your dental health, while others can cause disease -- we call the latter pathogenic.
  5. Your microbiome is relatively stable as long as the environmental factors are stable.
  6. When an imbalance arises in your mouth and pathogenic microorganisms become widespread, they can damage your teeth and oral tissues.
  7. Ill oral health is therefore first and foremost an ecological problem.
  8. Because your teeth do not shed cells from their surface, microorganisms can attach to them and build tiny communities called biofilm or dental plaque.
  9. Caries happens when microbial metabolism creates an acidic environment in which the protective layer of your teeth dissolves.
  10. The prime suspect in caries is a sugar-loving bacteria named Streptococcus mutans.

Some basic information about acid, erosion and caries

  1. The protective mineral layer around your teeth, the enamel, can be demineralized, i.e. damaged, by acid.
  2. When externally introduced acids eat away at large surface areas of enamel, this is erosion. Possible reasons may be acid reflux or overly generous consumption of acidic beverages such as wine or citrus fruit juice.
  3. When acid is produced within the dental plaque on a tooth's surface, this localised damage is called caries.
  4. After consumption of sugar, or fermentable carbohydrates more generally, the acidity within plaque is known to increase sharply. It will be brought back down over around a thirty minute time window as saliva does its job. This time window of acidity is when caries lesions progress.

Some basic ideas for maintaining oral health

In the long run, oral health is an outcome of
  • how healthy a microbiome you manage to cultivate,
  • how well you can manage the effects of your current microbiome at any time.
Here are some basic ideas for both of those.
  1. Consume little sugar to avoid making your mouth an attractive feeding ground for S. mutans.
  2. Eat at only a few occasions each day, ideally three or less, to avoid repeated feeding.
  3. The role of starches is not completely understood, but it seems that certain kinds of starches can cause similar problems as sugar. This is mostly because of two factors: they can stick to your teeth and they can be broken down into sugar. As a rule of thumb, anything that is particularly bad for diabetics is likely also bad for your oral health.
  4. Your saliva is your body's most important tool for keeping your mouth healthy. After eating you want plenty of non-acidic saliva around your teeth.
  5. By brushing your teeth you can mechanically remove a huge amount of microorganisms, including those that are likely to cause problems.
  6. Brushing your teeth is the most consistently advised measure against damage to teeth and gums. Most cultures today advice to brush two or three times a day.
  7. The best time to brush your teeth is before having a meal. Your goal is to remove microorganisms, not leftover food. If you brush after eating, you will cause two problems:
    • You will feed more microorganisms, who will rapidly metabolise the nutrients in your mouth.
    • You will brush your freshly softened teeth and contribute to demineralization.
    The problem with this advice is that it is based on theory, there seem to be no great studies confirming it empirically.
  8. It is helpful to end your meal with food that leaves your mouth in a good state. Many kinds of cheese help increase saliva flow, provide calcium for remineralization and help create a slightly alkaline environment.
  9. It is still a good idea to remove leftover food from your mouth. Rinsing your mouth with water is a good idea, as is the use of sugar-free chewing gum.
  10. The dangers of our modern diets can be counterbalanced by fluoride. Most toothpaste today contains fluoride, which is used to rebuild your teeth's enamel layer.

Personal Regiment

Initial Situation

My research into oral health comes in response to a post-pandemic visit to the dentist and the diagnosis of multiple sites of caries as well as inflammed and slightly pocketed gums.

These are the same kinds of issues that have been repeatedly reported and treated in the past. (Because of having lived in various cities, I saw a series of different dentists.) Several years ago I got serious about sticking to the suggested hygiene regiment: toothbrushing twice daily with a fluoridated tooth paste and a sonic toothbrush, daily use of floss, use of fluoride jelly once per week.

In addition, I already ate a vegetarian, relatively low sugar diet with lots of home cooking and little preprocessed foods. Lots of Italian-style pasta.

A plaque index created by my dentist showed only minor presence of plaque on the surfaces between the molars.

So my lifestyle does not seem to be a great predictor of my minor but persistent dental health issues. Unfortunately dentists in my area seem to run out of ideas for further analysis and prevention fast, and their only remaining strategy is periodic surgical treatment.


I am trying out a multitude of things in response and hope to see an overall improvement. I can probably not stick to all of these indefinitely, but my hope is that it will become clear over time what works and what doesn’t.

I am writing this list in the beginning of March 2021, with the intention to report on results later in the year.

Oral Hygiene Changes

  • Added daily use of interdental brushes to my nightly oral hygiene habits. After a few weeks I figured out how to use them without poking my gums and it works OK.
  • Started oil pulling with coconut oil in the morning. There are some studies which don’t look completely bogus and report positive effects. Overall it isn’t clear if or why or how this works, but then the same is true for many things dentists recommend. If it’s quackery, well OK, I kind of like the taste of coconut oil.
  • Picked up a new brand of sugar-free chewing gum, with a defined and high dose of xylitol to get to the recommended 6 g per day. These are for chewing after meals.
  • Started using probiotic lozenges containing an active strand of Lactobacillus reuteri. This bacterium is supposed to push out S. mutans and has been shown to improve markers of oral health. It however seems to wash out, meaning it is usually not able to build a sustainable population and needs to be resupplied. In Germany this is branded as GUM PerioBalance.
  • Started using a tooth paste with CPP-ACP in an attempt to remineralize carious sites. This is supposed to combine well with fluoride tooth paste.

Dietary Changes

  • Cut out free sugar wherever possible. So no sweets, no cakes, no honey, no nothing. This isn’t too hard for me personally, as I was never much of a sweet tooth.
  • Using xylitol as a sugar replacement is quite feasible in terms of taste, though it doesn’t have all the same structural properties as regular sugar.
  • Drastically reduced refined starches and white flour. We bake our own bread and I now put in whole grains in addition to using whole meal flour. We also now cook whole meal pasta instead of regular durum pasta. So far my partner indulges me. We still eat basmati rice.
  • Reduced the amount of sweet fruit I eat, such as bananas or oranges.
  • Limited the amount of alcohol consumed. It seems that beer due to its calories and the way it is normally consumed (over the course of an evening) is particularly likely to impact teeth. I now have an occasional drink with dinner.

I have already been (unreligiously) following an intermittent fasting lifestyle, though I don’t look at it as fasting, really. I just usually only eat twice a day.

Research Principles

The purpose of this website is to gather actionable information, providing scientific context.

While theory-building is useful, it seems that a lot of basic questions about oral health do not yet possess a reliable theory. Prominent examples to give are the roles of S. mutans and fluoride in oral health. There seems to be enough evidence to conclude that they are an important factor, but the working model of how exactly they fit into the bigger picture keeps shifting (Fejerskov 2004).

Therefore it seems wise to prefer research that measures direct effects we are interested in, rather than measuring factors that are only connected to outcomes via brittle theory. To give a concrete example, a study that establishes that a certain intervention reduces the amount of S. mutans is not as valuable as a study that directly establishes that an intervention reduces caries.


There is a combination of reasons why it pays to think about the subtleties of your oral hygiene habits:

Cleaning tools

  1. Electric toothbrushes seem to perform better from the standpoint of avoiding plaque and gingivitis compared with manual brushing. The difference is not dramatic but probably relevant over the long term (Yaacob and Glenny 2014).
  2. There is little evidence about which interdental cleaning method works best. In fact, we don’t seem to have a very clear understanding of how much of an additional benefit interdental cleaning has (Worthington and Clarkson 2019). (Yours truly chooses to floss daily nonetheless.)

Sequence of cleaning

  1. There seems to be some evidence that plaque removal is more effective when brushing after interdental cleaning with floss (Mazhari et al. 2018). It seems plausible to assume that the same is true with other interdental cleaning techniques.
  2. When using fluoridated toothpaste, it is often advised not to wash out the toothpaste after brushing, to give more time for absorption of fluoride.

Impact of Specific Foods and Beverages


The most important food group to be aware of are carbohydrates. There are three divisions among carbohydrates that it is important to keep apart:

  • Sugars
  • Starches
  • Fibers

Sugars and starches both store and provide energy. Fibers mainly give structure to food and are not digestible easily or at all. Sugar is acted upon directly by some oral bacteria, whereas starches need to be broken down first.

It is good to keep in mind that sugar and starch store energy. They provide energy to us, but they are also nutritious to various little microorganisms.



The situation with starches is much more subtle compared with that with sugars. It seems that S. mutans and friends can not make direct use of starches. However, amylase enzymes present in your saliva will start breaking down starches into sugars. If that happens, the bacteria will feast on them all over again.

From an oral health perspective, starches can be safe to eat. The scientific way to say this is that total starch intake is not correlated with increased risk of caries, but intake of rapidly digestible starches is (Halvorsrud et al. 2019).

The decisive questions with starches seem to be:

  • How long will the starches stay in your mouth?
  • How rapidly can the starches be broken down into sugars?

After a meal you want to avoid starches from sticking to and between your teeth, where salivary amylase will dissolve them into sugars. Potatoe chips are a likely culprit here (Lingstrom, Houte, and Kashket 2000).

Stickiness of Starches Makes Sugar Worse

It is also worth noting that starches, which are not quickly dissolved, may keep sugars around your teeth for a longer time when the two are mixed. Sugars by themselves often dissolve and leave the mouth quickly. But when mixed up with starch, for example in cookies, a clump may stick to your teeth and resupply the bacteria with sugar over an extended period.



It is clear that consuming alcohol with great frequency and volume is linked to ill effects on oral health. What is not so clear is which of these effects are due to direct action of alcohol on the oral ecosystem, and which are secondary effects of the unhealthy behaviours alcohol consumption may provoke (Grocock 2018).

The focus here will be on the general dietary effects of common alcoholic drinks, assuming moderate consumption.


Wine is low in sugar but high in acidity. White wine is more acidic than red wine.


Fejerskov, O. 2004. “Changing Paradigms in Concepts on Dental Caries: Consequences for Oral Health Care.” Caries Research 38 (3): 182–91.
Grocock, R. 2018. “The Relevance of Alcohol to Dental Practice.” BDJ Team 5 (2): 18025.
Halvorsrud, K., J. Lewney, D. Craig, and P. J. Moynihan. 2019. “Effects of Starch on Oral Health: Systematic Review to Inform WHO Guideline.” Journal of Dental Research 98 (1): 46–53.
Lingstrom, P., J. van Houte, and S. Kashket. 2000. “Food Starches and Dental Caries.” Critical Reviews in Oral Biology & Medicine 11 (3): 366–80.
Mazhari, Fatemeh, Marzie Boskabady, Amir Moeintaghavi, and Atieh Habibi. 2018. “The Effect of Toothbrushing and Flossing Sequence on Interdental Plaque Reduction and Fluoride Retention: A Randomized Controlled Clinical Trial.” Journal of Periodontology 89 (7): 824–32.
Worthington, MacDonald, HV, and JE Clarkson. 2019. “Home Use of Interdental Cleaning Devices, in Addition to Toothbrushing, for Preventing and Controlling Periodontal Diseases and Dental Caries.” Cochrane Database of Systematic Reviews, no. 4.
Yaacob, Worthington, M, and AM Glenny. 2014. “Powered Versus Manual Toothbrushing for Oral Health.” Cochrane Database of Systematic Reviews, no. 6.