I believe you're referring to this 2013 announcement from King's College, Biological tooth replacement -- a step closer. So called "BioTeeth" are sought after because
Current implant-based methods of whole tooth replacement fail to reproduce a natural root structure and as a consequence of the friction from eating and other jaw movement, loss of jaw bone can occur around the implant.
However, Professor Sharpe identified the following obstacle:
What is required is the identification of adult sources of human epithelial and mesenchymal cells that can be obtained in sufficient numbers to make biotooth formation a viable alternative to dental implants.
For some background, consult Biological tooth replacement (2006; Sartaj, Sharpe)
Unfortunately the 2013 article was the last I heard of it - possibly for the aforementioned reason. If you're really interested, you might consider attempting to contact Professor Sharpe yourself.