Tooth truths.
Text: Angelika JacobsIs honey better for teeth than ordinary sugar? And should you always wait half an hour before brushing your teeth after a meal? Five questions and answers on sugary treats, teeth and toothpaste.
What types of sugar are particularly harmful to teeth?
Oral bacteria can ferment different sugars including sucrose (table sugar), glucose (dextrose) and fructose (fruit sugar). This process produces acids that dissolve minerals out of the tooth enamel, potentially resulting in tooth decay. Sucrose is considered the most cariogenic carbohydrate, as certain bacteria convert it into extracellular polysaccharides that encourage the build-up and adhesion of biofilm on the tooth surface. On the other hand, sugar alcohols such as xylitol or erythritol and sweeteners such as aspartame are a much poorer source of nutrition for the bacteria and are therefore considered to be kinder to teeth.
Are natural sweeteners such as honey or date syrup better?
These natural sweeteners also contain fermentable sugars and are not automatically less harmful to teeth simply because they are “natural.” Although honey contains other constituents with antimicrobial properties, current research has not established that honey is a tooth-friendly alternative to table sugar. The same applies to fruit juices or smoothies. Whole fruit is better because the sugars are still embedded in the fruit’s natural cell structure and because the action of chewing stimulates salivation.
What has the greatest impact on dental health: the amount of sugar, oral hygiene or a person’s genetic predisposition?
It’s clear that the greater the volume of free sugars a person consumes, the higher the risk of tooth decay. As well as the overall amount, frequency of consumption also plays a role. People who constantly nibble on sweet foods or sip sugary drinks keep the environment around their teeth acidic for long periods of time. Although regular brushing with fluoride toothpaste reduces the risk of decay, it cannot fully counteract the effects of high sugar consumption. Genetic factors can also influence an individual’s susceptibility to tooth decay — for example, via properties of the enamel or saliva. Nevertheless, people shouldn’t rely on genetic factors just because their grandmother rarely had tooth decay. Reducing sugar intake and taking care of your teeth are better forms of protection.
We often hear that we should wait half an hour before brushing our teeth after meals. Is that true?
This recommendation relates less to sugar and more to acidic food and drinks. It was previously assumed that brushing your teeth after exposure to acid was even more harmful to the enamel, but more recent analyses show no clear advantage to always waiting 30 minutes. After consuming highly acidic food or drinks, you can rinse your mouth with water first to help remove residual acids. In any case, it’s better to brush immediately with fluoride toothpaste than to wait half an hour and then forget to do so.
Can you still eat sugar-free foods in the evening after brushing your teeth?
The label “sugar-free” doesn’t automatically mean that a foodstuff is kind to the teeth. Indeed, some sugar-free products contain acids that can attack the enamel. Foods such as cheese are less problematic and can even help neutralize acids and protect teeth by stimulating saliva production and providing calcium and phosphate. Nevertheless, after brushing your teeth, it’s best not to eat anything else and to drink, at most, water. The key thing is for the fluoride from the toothpaste to remain on the teeth for as long as possible and to help remineralize the enamel.
Information was provided by Monika Astasov-Frauenhoffer and Viktoriya Shyp, co-group leaders in oral microbiology at the University Center for Dental Medicine Basel UZB.
More articles in this issue of UNI NOVA (November 2026).