Scientists grow teeth in lab

Dr Pamela Yelick examines tooth development

By Dr David Whitehouse BBC News Online science editor

Scientists have successfully used tissue engineering techniques to grow almost fully formed teeth.

It points the way for biologic repair in dental disease

Dr Joseph Vacanti

They believe the breakthrough could eventually lead to a biological tooth substitute to replace human teeth.

The researchers made a suspension of individual cells from a young tooth reorganise into a tooth crown containing both enamel and dentin.

Dr Pamela Yelick told BBC News Online that it might be possible one day to grow human teeth of a particular size and shape.

She predicted that within five years, we would know whether dental stem cells could be manipulated to bioengineer teeth. To generate a human tooth might take an additional five to 10 years.

Pigs to rats

Writing in the Journal of Dental Research, the researchers describe how they used enzymes to isolate immature tooth cells from six-month-old pigs.

Enamel (white) develops in the implants after 30 weeks

They then seeded cells obtained from the immature teeth of the animals on to sponge-like biodegradable polymer scaffolds and placed them inside rats to develop.

Within 30 weeks, they report, small, recognisable tooth crowns had formed, containing all the materials found in normal teeth.

That is, dentin (a bone-like layer); odontoblasts (cells that secrete dentin); a well-defined pulp chamber; cementoblasts (cells that cover the roots of the tooth); and enamel.

The researchers say their work is the first successful production of mature tooth crowns containing both dentin and enamel.

Other experts have used alternative approaches to form partial tooth structures, including dentin and pulp, but none have so far grown complete structures that include enamel.

Dental repair

Dr Joseph Vacanti, director of the Laboratory for Tissue Engineering and Organ Fabrication at Massachusetts General Hospital (MGH), US, and a co-researcher on the project said: "It points the way for biologic repair in dental disease, using the new tools of tissue engineering."

Of great importance, say the scientists, is the discovery that dental stem cells appear to exist in pig molar tissues.

Researcher Dr Conan Young with the new teeth

"It suggests the existence of stem cells that could be important in many areas of dental repair," said Dr Vacanti.

"By combining the new science of stem cell biology with the engineering concepts and techniques of tissue engineering, it demonstrates that complex structures such as living teeth can be created.

Dr Dominick DePaola, of the Forsyth Institute, where the work was carried out, added: "The ability to identify, isolate and propagate dental stem cells to use in biological replacement tooth therapy has the potential to revolutionise dentistry."

And Dr Bruce Donoff, of the Harvard School of Dental Medicine Center for Craniofacial Tissue Engineering, said: "The potential of this advance is enormous and could have a far-reaching impact on patient care."

Natural replacement

Currently used synthetic tooth implants often provide effective replacements, though they do not wear as well as natural teeth.

Moreover, as a person's bite changes with age, such implants do not move naturally in the jaw.

Ideally, biological teeth would have all the same properties of an individual's natural teeth.

They would be the same size and shape, and would fit just as well as the originals.