17 January 2024

Answering the questions that are on the tip of your tongue. KHP interviews Dr Saoirse O'Toole [pictured below], clinical lecturer in prosthodontics at the Faculty of Dentistry, Oral & Craniofacial Sciences, King’s College London, to learn more about improving oral hygiene.

What does a day in the life look like for a clinical lecturer in prosthodontics?

Prosthodontics is the branch of dentistry focused on replacing and rebuilding missing teeth and missing tooth structure. My research is related to erosive wear of the teeth where acids and mechanical challenges such as tooth grinding and toothbrush abrasion wear down the teeth, shortening their dental life span. This affects up to a third of the population and is most common in those with gastric reflux, chronic vomiting, eating disorders, and bruxism. I am also interested in dental sleep medicine and 3D imaging in dentistry. 

What are some of the things people could do to improve the health of their teeth?

People underestimate the importance of flossing (interdental cleaning) and diet. Flossing or cleaning in between the teeth is necessary to keep the gums healthy. It is awful to see healthy teeth coming out because the gums aren't healthy enough to hold them in. A good trick that was told to me recently was to make it a habit to floss before you brush.

When you brush first it can feel like your teeth are clean which can tempt you to skip flossing, but if you floss before then it's very unlikely you’ll skip brushing afterwards. Try to floss every day but if you miss a day just make sure you get to it the next day. Research has shown that planning the time when you are going to do it in advance and putting a visible reminder up can help you develop the habit. 

When looking at the diet, look for sugars and acids. Frequency can be more important than what you are having. For example, if you are snacking on a punnet of grapes and eating one at a time over a long period, this is a lot worse for your teeth than if you eat twenty grapes in one go. It’s the same with sugar in tea and coffee - multiple intakes over the day will not allow the teeth to recover and will cause dental decay. Try and have any acids and sugar with meals. 

Try to avoid adding unnecessary acids to drinks. Fruit, fruit flavours (i.e. cordial) and hot lemon in water have become quite popular but these acidic drinks can cause severe dental sensitivity and in the long term can cause acid damage.

Our teeth are 98% mineral, so acidic drinks can wear away our teeth. One way around this is adding mint or cucumber to your water - it's a good way of adding flavour while avoiding the acidic consequences. Fruit is still a vital part of a healthy diet though, so from a dental point of view we can handle juices and flavourings, if it helps to get more fruit into people’s diets.

Avoid rinsing with water after you brush so the fluoride can stay on the teeth. When you rinse you remove the fluoride that helps remineralise all the dental structures. 

Is there anything people can do to get a naturally whiter smile?

Teeth discolour over time because of our diets. Tea, coffees, turmeric, red wine - all of these things stain our teeth over time and there is little we can do apart from reducing the frequency and maintaining good oral hygiene to reduce staining.

Regular cleans with a dental hygienist will remove the stains periodically. If you want whiter teeth in general, the safest way to do it is through a home whitening kit provided by your dentist. That will whiten the teeth with minimal damage provided it's not done long term. I don't recommend whitening toothpastes, particularly if you have a high acidity diet.

Whitening toothpastes work by being abrasive and physically removing the stains, but they can also remove the top layer of the teeth and that's why whitening toothpastes can be detrimental. It’s the same with whitening strips - they have very high concentrations of acid and abrasivity, which can erode and strip away the teeth.

Is there a best time to brush?

Before you go to bed at night is the most important time to brush your teeth, because when you sleep saliva levels drop and whatever bits are stuck in your teeth will be there for the night. For the morning we used to think you shouldn’t brush your teeth immediately after breakfast, because you could be abrading your teeth if you had fruit with your breakfast.

However, research has shown this not to be the case. The damage is done with any acid or sugary food already and brushing immediately after breakfast shouldn't do any more harm than brushing beforehand - anytime in the morning is ok. We recommend brushing last thing before you go to bed at night and one other time during the day. 

How can we find the right products for our teeth? 

If you have sensitive teeth, the first step is to reduce the frequency of acids in your diet. Following that sensitive tooth products do work. You can speed up the process by smearing a small amount of the toothpaste over the sensitive area before you go to bed.

Different products work in different ways so sometimes it's just a case of trial and error to find which one works for you. With regards to rest of the toothpastes, I use any toothpaste with fluoride. I also try to pick one with low abrasivity which excludes most whitening toothpastes. Most sensitivity toothpastes have low abrasivity and anyone can use them - as long as it contains fluoride. 

Can oral care be more sustainable?

It's a horrible fact that every single tube of toothpaste that you've ever used is still in the world somewhere unless it's been burned. Dentistry creates a lot of plastic - toothbrushes, toothpaste tubes - even floss is a single use plastic. Bamboo toothbrushes are becoming more available but even with these you still have to remove the plastic fibrils that you use to brush your teeth.

There are chewable toothpaste tablets now on the market which could reduce our carbon footprint - they are relatively new so we don't have any research on them to date, but maybe that will come. We don’t have a substitute for floss yet, but I think these products will come.

How can people address treatment phobias? 

At King’s College London we have a whole department dedicated to helping people with dental phobias and anxieties. The King’s College London’s Faculty of Dentistry, Oral & Craniofacial Sciences has a longstanding partnership working with Guy’s and St Thomas’ NHS Foundation Trust (NHS FT) to find out more about dental phobia to help people conquer their fear.

Cognitive Behavioural Therapy has been shown to be successful in helping patients with dental phobias get the care they need. Through our work with Guy’s and St Thomas’ NHS FT we have also been exploring whether virtual reality technology could help treat people with dental phobia by replicating dental experiences using virtual reality headsets, which again may be promising for dental phobia. For less severe phobias, I think just being upfront about it and telling your dentist about it will help.

Letting them know you are anxious and asking them to explain everything before they start can give you back a sense of control. It can also help to recognise that dentistry in the past is not what dentistry is like now. Dentists have training on how to manage dental phobias our understanding of how to manage pain and create a more relaxing experience is better. Also our aim is to be as minimally invasive as possible which makes the experience far more manageable than it was in the past. 

The King’s Health Partners Dental Clinical Academic Group provides dental care for more than 300,000 patients each year at more than 30 sites across London.