Dr Samantha Byrne

Samantha Byrne is a a lecturer in Oral Biology at the Melbourne Dental School. She also researches the bacteria that cause tooth decay and gum diseases. Samantha started The Tooth Fairy blog as a way to share information about dental hygiene and advice on teaching kids how to look after their teeth.

We got to chat to Samantha about what her works invovles, what actually causes tooth decay and how we can keep our pearly whites, pearly white!

What originally stimulated your interest in oral hygiene and microbiology?
I always loved science at school, and also loved working with my hands so I thought dentistry would be a good mix of both. After working as a dentist for 4 years I decided to give up clinical dentistry and do a PhD in oral microbiology as that was the area I found most interesting.

My work days are a wonderful mix of laboratory research and teaching at the Melbourne Dental School. In the lab we are investigating the bacteria that cause tooth decay and gum diseases and I really enjoy the combination of problem solving and discovery. When I am teaching, my students are learning about oral diseases and most importantly, how they can help their patients prevent them which is very satisfying to be a part of.

I started The Tooth Fairy because tooth decay is a very common yet preventable disease in children. With my background, and as a mum of 3 little boys I wanted to share information about how to prevent tooth decay.

What role does our diet play in keeping our teeth healthy?
Diet plays a very important part in keeping teeth healthy and can be both damaging and protective. Tooth decay is caused when the bacteria that live in our mouths turn the sugar we eat into acid. This acid damages the teeth by dissolving them. Early on, this damage can be repaired and certain things in the diet can help with this repair. Unsweetened dairy products can help repair teeth and protect against tooth decay, and foods that need a lot of chewing and stimulate saliva flow also help keep teeth healthy.

Why are we seeing increasing rates of tooth decay in children?
Tooth decay is a major problem amongst Australian children with approximately half of all 6 year olds having tooth decay in their baby teeth. This is very concerning, as tooth decay is largely a preventable disease.

The biggest factor contributing to tooth decay is sugar in the diet. It is not only the total amount of sugar, but the frequency of consuming that sugar during the day.

How does sugar affect our teeth?
Tooth decay is caused when the bacteria that live in our mouths turn the sugar we eat into acid. This acid then damages the tooth by dissolving the hard tooth structure. If this damage is allowed to continue, the result is tooth decay.

What is the difference between refined, added and free sugar?
Refined sugar is usually referring to sucrose either in white, raw or liquid form that has been manufactured for addition to food.

Free sugars are defined by the World Health Organisation as sugars which are added to foods and drinks by the manufacturer, cook or consumer and sugars naturally present in honey, syrups, fruit juices and fruit juice concentrates. Added sugars are any sugars that have been added to foods including sugars other than refined sugars.

When it comes to tooth decay, the bacteria in the mouth are not fussy and will turn just about any sugar we give them into acid. This means that not only refined sugar but sugar in fruit juice, honey, maple syrup, rice malt syrup, coconut sugar, pureed dates will all be turned into acid. So just because something is ‘refined sugar free’ doesn’t necessarily mean it is any better for our teeth.

Why are dairy products good for our teeth? What do you recommend for people with a dairy intolerance?
Unsweetened dairy products are good for teeth for a number of reasons. Teeth are made mostly of calcium and phosphate crystals, and milk contains lots and lots of calcium and phosphate. The calcium and phosphate in dairy products are able to be taken up into the tooth and help repair the damage caused by bacteria. What is extra special about dairy is the proteins that are present which help the calcium and phosphate repair this damage. Dairy can also buffer or remove acid from the mouth, helping to prevent acid damage.

For people with lactose intolerance, choosing lactose-free products will provide the same benefits.

For dairy intolerance however, there is really no other alternative that matches the benefits of dairy to teeth. But maintaining healthy saliva levels will help protect and repair teeth too.

What is your advice on maintaining healthy saliva? What are your thoughts on chewing gum?
Having plenty of saliva around is really important for maintaining healthy teeth. This is because saliva contains lots of calcium and phosphate which helps repair acid damage caused by bacteria. Saliva also washes away foods and acids from the mouth and protects teeth against wear when chewing.

Chewing sugar-free gum is a great way to stimulate the flow of saliva, and very handy to use during the day after eating or drinking.

What is your advice on maintaining healthy teeth and diets for time-poor people?
Make best friends with your freezer and prepare your own food as much as possible. We cook big batches of dishes that can be frozen for quick dinners at the end of busy days. Choose whole fruits and vegetables as snacks rather than processed foods which often contain a lot of added sugar. We stick to the same brands of things like cereal and yoghurt with low amounts of sugar which makes shopping much quicker.

Drink plenty of water during the day. Children in particular should drink water rather than fruit juice or cordial during the day.

And make tooth cleaning after breakfast and before bed not negotiable. I know what it is like trying to get three children out the door in the morning it is much easier when tooth brushing part of your daily routine.

What are your favourite sugar-free snacks or party foods for kids?
At my son’s 6th birthday party recently we served fruit skewers and baby carrots with hummus dip which were both very popular with the children and parents! My favourite pantry snack that works for pretty much every occasion is plain popcorn.

When avoiding hidden sugars, what types of food do we need to look out for?
In the supermarket, when avoiding hidden sugars, you really do have to read nutritional panels of any food that has been processed. One of the tricky things about trying to avoid hidden sugars is that sugar has many different names, so simply reading a list of ingredients can be confusing! Breakfast cereals, muesli bars, yoghurt and even savoury biscuits can have surprisingly high amounts of sugar. Smoothies are very popular at the moment and many of them can contain well over the daily recommended sugar intake!

Thanks for the very insightful chat Samantha! A fantastic resource for anyone wanting some clear and handy information on dental hygiene.

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