– Science with real bite: Full set of teeth grown in the lab (Daily Mail, July 13 2011):
Scientists have grown fully formed teeth from stem cells.
The artificial teeth looked like the real thing, were sensitive to pain and could chew food.
The breakthrough was made on mice but could pave the way for those who lose teeth to decay or injury being able to ‘grow’ replacements.
The researchers harnessed the power of stem cells – ‘master cells’ which have the potential to be used to grow any part of the body – to generate teeth.
Two types of stem cell which between them contain all the instructions for making teeth were mixed together and grown in the lab in a mixture of chemicals and vitamins that started their transformation.
After five days, they had formed a tiny ‘tooth bud’. The fledgling tooth was then placed in a tailor-made plastic box deep inside a mouse’s body, where over the next 60 days it grew to form a full tooth.
While this might seem bizarre, putting it inside the body ensured it had access to the fluids and chemical signals it needed to develop further.
When fully grown, it was taken out of the box and transplanted deep into the jawbone of a mouse that had had a tooth removed.
Six weeks later, it had fused with the jawbone, the journal PLoS ONE reports. The tooth had all the components of normal teeth, including enamel, crown and root, and connective fibres to fix it to bone.
The researchers, from Tokyo University of Science, have previously transplanted tooth buds into mice and watched and waited for them to break through the gum.
But given how slowly human teeth grow, they think transplanting fully-formed teeth is much more practical.
Human teeth bioengineered in this way could provide a more natural-looking alternative to false teeth and synthetic implants.
A tooth that matches the real thing would also have psychological benefits for patients.
‘The bioengineered teeth were fully functional … there was no trouble biting and eating food after transplantation,’ wrote Masamitsu Oshima, assistant professor at the Research Institute for Science and Technology, Tokyo University of Science.
The researchers hope this is a step towards the development of new human organs grown from a patient’s own cells.
‘At present, researchers worldwide do not have the method to culture three-dimensional organs in vitro (outside the body),’ Professor Takashi Tsuji, who led the research, said.
‘It is important to develop technologies for the culture of the bioengineered organ … for the realization of future organ replacement regenerative therapy.’
Likely to cost around £2,000 each – the same as the implants used at the moment – the stem cell teeth may also produce a more natural ‘bite’.
However, the research is still at an early stage and researchers say it will be at least a decade before people can ‘grow their own teeth’.
Hurdles to be overcome include finding a suitable source of stem cells for use in the human mouth.
Damien Walmsley, scientific advisor to the British Dental Association, warned the bioengineering was still a long way from being something that will directly benefit patients.
‘For the foreseeable future, it is important patients brush twice a day with fluoride toothpaste, restrict their intake of sugary food and drinks and visit their dentist regularly,’ he said.