A team of researchers believe they have discovered a way to trigger teeth regeneration which would allow them to regrow and even fix cavities.
The team from King’s College, London, conducted a study last year where they showed that mice teeth could be treated with various drugs to trigger the teeth to rebuild themselves.
The treatment involves using a series of drugs to activate stem cells at the base of the tooth, called the tooth pulp.
Stem cells, which can transform into almost any other cell, then begin to regrow the parts of the teeth that have been lost to accident or decay.
Scientists have more recently replicated their results in rats, who have teeth more similar to those of humans, making it more likely that this technology will eventually work in humans.
The team are now looking at human trials in the near future.
An early study identified the presence of the Wnt pathway in tooth pulp. This is a form of communication between cells, typically involved in self-repair around the body, for example, the brain and intestines.
Using this as a springboard, the team from King’s College investigated whether the stem cells already present in tooth pulp could be triggered in any way to activate this pathway and extend the restorative abilities of teeth.
Teeth already have minor regenerative abilities: for instance, when the dentin layer, which lies beneath the hard outer layer but before the pulp, is damaged. The stem cells in the pulp quickly turn into odontoblasts to fix them.
However, if the damage is too great, for instance, if the teeth are broken or haven’t been brushed in a long time, the stem cells can’t do anything, which leads to cavities.
In their study last year, the scientists drilled holes into the molars of mice. They then soaked tiny sponges in various drugs, picked because they were known to stimulate the Wnt pathway, and these were placed inside the cavities.
The sponges were left for four to six weeks, after which the majority of the cavities showed some degree of healing.
This shows that the stem cells had been stimulated to heal the tooth, even when it was badly damaged.
‘It was essentially a complete repair,’ Professor Paul Sharpe, study co-author, said. ‘You can barely see the joint where the old and new dentin meet. This could eventually be the first routine pharmaceutical treatment in dentistry.’
Since last year, the researchers have repeated the study on rats, because the teeth of rats are larger and closer to those of humans.
They found the treatment worked in them as well, although the results of this latest study are still to be published.
Besides that, the researchers have developed a gel that can be injected into teeth, in the hopes this will be easier to administer by dentists.
They are now looking forward to clinical human trials.
Professor Sharpe says that these trials may still be several years away. However, he hopes that, because many of the drugs used in the study are already in use in medicine, the process of approval will be quick.
Scientists says, if they succeed, this could represent one of the greatest steps forward in dentistry in the last 50 years.
There is a small risk in the use of stem cells. Stem cells can cause uncontrolled tissue growth: for instance, there have been cases where the administering the cells in one area has lead to small brain tumours, or bone growing in the eyelids.