Dagmar Else Slot, the first dental hygienist in the Netherlands to become a professor, conducts research on prevention in oral care at the Academic Centre for Dentistry Amsterdam (ACTA). She provides us with a definitive answer to the prevailing question: how should we really care for our teeth?
You are now a professor, but you started your career as a dental hygienist. Do you think the academic world could benefit from more people from the field?
'Absolutely. In oral care, the number of professors still actively practising is minimal. There are a few dentists, but many haven't seen a patient in years. I find this hands-on experience valuable. Similarly, I value teaching, which is why I'm the director of the master’s program in HGZO education at the VU, where healthcare professionals learn to become teachers through a teaching master's.
During my studies, I realized I needed more freedom to truly flourish, which I found more in research. However, I still work every Monday as a dental hygienist in general practice. When patients ask me about a new mouthwash or a particular toothpaste, I sometimes don’t know and will look it up or suggest it as a topic for a master’s or bachelor’s thesis.'
Let’s go back to basics: why do we need to brush our teeth? Haven’t we evolved past the need for it?
'In the age of hunters and gatherers, people didn’t brush their teeth as we do, but their diet was entirely different. They often ate once a day and consumed different foods than we do now. Our current diet causes harmful plaque to form in our mouths, which leads to cavities and gum disease. Removing this plaque is primarily done with a toothbrush. For cleaning between the teeth, there are various tools available: floss, toothpicks, interdental brushes, and oral irrigators, each with different effects and specific uses.'
Do you see different bacteria in the mouth today compared to the past?
'The composition of the tartar found in ancient humans is indeed different from today's dental plaque. Indigenous populations with minimal contact with others and modern foods have fewer oral health problems. They maintain a natural balance, while we tend to have an imbalance.'
You often hear negative reports about fluoride use. However, what's really going on?
'In large cities, we see vaccination rates for children from higher-income families declining, and this is the same group that often avoids fluoride. This is usually a well-meaning choice, but scientifically, fluoride is not proven to be harmful. On the contrary, it is essential for strong and healthy teeth to be capable of withstanding our current diet and imbalance.
Fluoride integrates into your tooth enamel, keeping it strong. When you eat or drink, the pH level in your mouth drops. Fluoride helps the enamel stay hard, protecting against these acidic attacks. Think of it as starting with a brick wall; eating and drinking wear down the mortar. Fluoride helps keep that mortar strong and durable.'
Do you also see in practice that there is a socio-economic factor related to oral health prevention?
'In a city like Amsterdam, about 30,000 children don’t visit the dentist, indicating socio-economic issues. Sometimes it’s also a cultural problem. In the Netherlands, we’re used to biannual check-ups, but in France or Spain, you only see the dentist when you’re in pain or want a cleaning.
In eateries with foreign cuisines, you often see wooden cocktail sticks on the table used to remove food from between teeth. This is different from removing plaque and stimulating gums with triangular wooden toothpicks.'
What’s the secret to a healthy mouth?
'The big question is whether to brush before or after breakfast. Both have their merits. Brushing before breakfast is fine, but it leaves less fluoride from the toothpaste. If you brush after breakfast, wait half an hour due to the acidic impact of the meal, which could otherwise damage your teeth if brushed immediately.
We recommend brushing again in the evening, preferably with an electric toothbrush, which is more effective than a manual one. It’s a myth that bad breath usually comes from stomach issues; it’s often due to gum disease or bacteria on the tongue. This can be prevented by cleaning the tongue, a practice common among people from the Antilles or Suriname but less so in the Netherlands.'
Finally: toothpicks, interdental brushes, or floss - when should we use which and in what order?
'Choose a product that suits your mouth and that you will use regularly. Clean between your teeth once a day. Flossing has been shown to be less effective for removing plaque and maintaining healthy gums. Other products are more effective.
Triangular wooden toothpicks are the easiest to use and can be used anywhere: at your laptop, in the car, or while watching TV. Interdental brushes are very effective, especially for those with severe gum disease, but they require the right size and can be tricky to use. It’s best to use interdental brushes before brushing your teeth. Using toothpaste on the brush can be too abrasive. Personalized advice from a dental professional is essential.
Mouthwash can be used, but will never be as effective as brushing with fluoride toothpaste and using an interdental tool.'
What do you foresee for the future of oral care?
'Prevention will become increasingly important. People are less inclined to age with dentures. I expect brushing to become easier, with AI-based devices taking over the task. Smart toothbrushes will continue to advance, and in a few years, we might have robots that can brush our teeth.'
