novamin crystals

Novamin acts to block the tiny holes in the dentine to help reduce the pain of sensitive teeth

How a chance encounter led to a world-first toothpaste

Did you know that NovaMin, one of the key technologies in our toothpaste, is actually a bioactive glass most commonly used to repair bones? Its creation stems from a chance encounter between a professor and a war veteran, and a resulting challenge to find a better way to fix shattered limbs.

One of the more compelling aspects of scientific research is the unexpected avenues down which it can lead. The exploratory nature of science means there is always the potential for unexpected results and happy accidents. In this way, serendipity has led to some of science’s more notable discoveries.

Any list of accidental scientific breakthroughs must surely be headed by Alexander Fleming’s fortuitous discovery of penicillin in 1928. Had Fleming bothered to tidy away his staphylococcus bacteria samples before leaving for a holiday, we might still be ignorant of the bacteria-fighting properties of the penicillium fungus that grew in his absence.

A key technology in our Sensodyne Repair & Protect toothpaste was also the beneficiary of scientific happenstance.

From broken bones to BIOGLASS

In August 1967, the late Professor Larry Hench was researching the resistant properties of glass to nuclear radiation, which took him to an army materials conference in New York. On the journey there, he found himself sitting next to a US army colonel who had just returned from Vietnam. During their conversation, Colonel Klinker, who had seen hundreds of limbs amputated every week in Vietnam because the patients’ bodies rejected the metals and plastics used to mend their bones, asked Hench a question which ultimately led to the discovery of NovaMin:

If you can make a material that will survive exposure to high-energy radiation, can you make a material that will survive exposure to the human body?

Hench believed there must be a better way of repairing shattered bones and started to work on materials that could bridge a gap where bone is missing. Up until this point biomaterials had been designed to be inert. But Hench realised that if a material could bond with bone the connection would be stronger. He started with the idea that as bone is primarily made of calcium and phosphorus, the material would need a source of this to bond with bone.

Two years later, after experimenting with different combinations of minerals, he found the right balance of calcium, phosphorus, sodium and silicate and Hench’s first bioactive glass was created. Trademarked as BIOGLASS, it has been successfully used in medicine ever since to mend bones and accelerate bone growth.

Like repairing holes in wall

If it hadn’t been for more inquisitive scientists, the story may have ended there. But in 1996 two dentists, Dr Len Litkowski and Dr Gary Hack, who were studying sensitive teeth, along with researcher Dr David Greenspan, experimented with using BIOGLASS on teeth. Teeth, like bones, are primarily made of calcium and phosphorus, and it was this structural similarity that made them consider experimenting.   

Dental hypersensitivity is caused by tiny holes in the dentine – the material which lies under the enamel and makes up the bulk of the tooth - that allow sensations like hot and cold to reach the nerves. The hypothesis was that BIOGLASS could fill the holes and stop the sensation reaching the nerves.

Their experiments showed that in the presence of water or saliva, calcium, sodium, silica and phosphorus react to form a calcium phosphate layer which crystallises to form hydroxyapatite. Hydroxyapatite is similar both chemically and structurally to the minerals in teeth and works to fill the holes, similar to using filler to repair holes in a wall. They called their formulation NovaMin, and at first it was only used in a few small products. 

In 2001, GSK acquired the Sensodyne brand and the Oral Healthcare R&D team soon started to think about how they could move the brand forward from a technology and science perspective, building upon its strong heritage. They wanted innovative technologies based on thorough scientific research to differentiate GSK’s Oral Healthcare products. This led them to investigate NovaMin. Speaking about what drove the team to find such technologies Teresa Layer, VP Oral Healthcare R&D, said:

We were, and still are, determined to be a speciality Oral Health business differentiated by great consumer insight and amazing science.

GSK formally acquired NovaMin in December 2009. However, work still needed to be done to take the original non-fluoride NovaMin toothpaste formulation and optimise it.

Fluoride is an essential ingredient for a daily toothpaste because it protects teeth from erosion and the challenge was to successfully combine this key component with Novamin.

Many months of experimentation began, and a little over a year later GSK was able to launch a world-first toothpaste combining the scientifically proven repairing properties of NovaMin, with fluoride’s protective capabilities to protect teeth from decay and erosion and combat dentine hypersensitivity. The result: Sensodyne Repair & Protect Toothpaste.

Novamin acts to block the tiny holes in the dentine to help reduce the pain of sensitive teeth.

"The living bond that NovaMin forms with the tooth makes the protective layer much sturdier and longer lasting," Teresa explained.

With over a third of adults suffering from sensitive teeth, the impact of reformulating Larry Hench’s bioactive glass for use in oral health has the potential to improve approximately 2.5 billion lives – a big impact from a chance encounter.