BERLIN. The approach of researchers at the Technical University of Berlin for natural third teeth sounds simple in principle: dental pulp cells are obtained from the inside of an extracted tooth, which are cultured and de-differentiated so that an active tooth germ is formed from them.

If this tooth germ is planted in a patient's jaw, it begins to communicate with the surrounding tissue and triggers tooth formation.

The approach has already worked in in vitro experiments, reports the TU: A team led by Professor Roland Lauster took pulp cells from wisdom teeth that had been operated on, separated them, cleaned them and then cultivated them in micro titer plates whose surface was coated with a hydrogel. The hydrogel prevented the cells from adhering to the wall of the titer plates.

The free-floating cells are programmed to strive for a three-dimensional structure, the TU informs: Within 24 hours, the cells therefore condensed independently into a cell ball of 200-500 micrometers in size.

The aggregation subsequently triggered the expression of various genes and set in motion the production of specific messenger substances. In humans, it is precisely these messengers that are needed to interact with the surrounding jaw tissue.

When the researchers co-cultured the tooth germs with cells from the gums, they demonstrated an interaction similar to that which occurs during embryonic tooth development.

Now that the in vitro trials have been successfully completed, the tooth germs are about to undergo their first preclinical tests, TU said. (bae)