Dr Zoe Laughlin, co-founder and director of the Institute of Making at University College London, is an artist, designer, maker and materials engineer. An infectiously enthusiastic presenter, she has made a variety of TV programmes about materials and describes her role as ‘explaining the art, craft, science and engineering of STUFF.’
As part of her investigation into what ingredients should be included in an ideal toothpaste, Zoe visited Professor Robert Hill in his labs to learn about the groundbreaking technology behind BioMin. Although BioMin could not be mentioned by name on the programme, Zoe said that there was only one brand which used the bioglass technology, and she was extremely excited by its innovation and its potential.
Narration: The toothbrush goes hand in hand with the toothpaste and just like brushes, pastes have become bewilderingly fancy. Even brushing twice a day with a fluoride paste doesn’t provide round the clock protection as the fluoride washes away over the course of a day.
Zoe Laughlin: Ah Robert, I’m Zoe Laughlin.
Narration: Professor Robert Hill and his team at Queen Mary University have created a new material to create an even better fluoride barrier.
Robert Hill: What we’ve developed is a special bioactive glass that dissolves in the saliva and as it dissolves it releases the fluoride.
Zoe: So, your fluoride is embedded in the glass?
Robert: Yes, and the glass is designed to stick to the teeth, so you get slow delivery over 10-12 hours.
Zoe: So, you’ve developed what sounds to me like a magic ingredient.
Robert: And you could say, if you like the word, that it’s a ‘smart’ material.
Zoe: So glass being in the toothpaste might make people go: crikey, I’m not going to put glass in my mouth, but I imagine these are very small particles?
Robert: Yes. The average particle size is about a 10th of the thickness of a human hair.
Zoe: How much like the traditional glass, that maybe we’d have in our windows, is it?
Robert: If you made your window panes out of this glass it would just dissolve when it rained then disappear.
Narration: This is the furnace room where the glass is going to be cast into water.
Zoe: I’m going to stand well back.
Narration: Robert’s silica glass encapsulates fluoride within its structure. The glass is heated to temperature of around 1,400° Celsius – incredible molten amber liquid – before being rapidly quenched in cold water. Fracturing into hundreds of tiny fragments of glass, like snow, in the bottom of the bucket. 'It’s quite heavy' (said carrying the bucket). The water is drained away leaving behind gritty chunks.
Robert: And we will now grind this glass to a fine powder that we can then use in the toothpaste.
Narration: The particles will go through more than 10 hours of grinding to reach the required size for a toothpaste.
Zoe: You can feel the fine powder.
Robert: Oh, that’s quite gritty.
Zoe (laughing): In your world that’s gritty, in my world that’s fine!
Narration: But the magic properties of this bioglass don’t stop at fluoride protection. Robert and his team have also added calcium and phosphate ions, two of the main minerals in tooth enamel.
Robert: So, in here we have our scanning electron microscope. These minerals mimic and attach to the tooth surface delivering the fluoride. But that’s not all. Here we have a picture of the dentinal tubules in a tooth and these tubules become exposed as a result of the enamel that you’ve lost on the tooth surface.
Narration: Without the enamel protection, substances like ice cream or hot soup can go right through these tubules to our nerves causing pain and sensitivity.
Robert: The solution is to block these tubules, and this is what we’ve done with the bioglass.
Zoe: Oh yeah.
Robert: And here we have the same section but now brushed with the bioglass toothpaste.
Zoe: So that’s your special bioglass bunging up the holes!
Robert: Bunging up the holes. That’s right.
Narration: Amazingly, the calcium and phosphate remineralise and restore the outer layer where the enamel has been worn away.
Zoe: So, your bioglass is actually doing two things. It’s releasing that protective fluoride, but it’s also blocking those dentinal tubules.
Robert: That’s exactly right. And that makes it a very effective ingredient for toothpastes.
After leaving the lab, Zoe was clearly very impressed with what she had seen.
Zoe: Right now, this innovative material is only available in one range of paste, and at nearly four times the price of many high street brands it doesn’t come cheap. But it offers an exciting future for the health of our teeth. I’m really thrilled because Robert has given me a little sachet of his bioglass powder. Magic stuff.
And once back at the Institute of Making, Zoe set about creating her own bespoke toothpaste, mixing the ingredients she had identified.
Zoe: Now for the futuristic bioglass. This amazing time-lapse fluoride releasing glass. This has GOT to be in there.