Over the last five years scientists at King’s College London have been investigating a method of stimulating natural tooth repair by activating cells in the tooth to make new dentine. In a paper published today in the Journal of Dental Research, they have found further positive evidence that the method has the potential to be translated into a direct clinical approach.
When teeth suffer damage either by decay or trauma, there are three layers that may be affected:
the outer enamel,
dentine, the middle part that shields the vital part of the tooth, and
the inner part of the tooth; the soft dental pulp.
Previous research has found that the drug Tideglusib could help protect the inner layer by stimulating the production of the middle layer (dentine), allowing the tooth to repair itself.
To continue testing the viability of this approach for use in patients, the research team have now looked at whether the volume of reparative dentine produced is sufficient to repair cavities found in human teeth. They also investigated the range (and hence safety) of the drug used, and whether the mineral composition of the reparative dentine sufficiently is similar to normal dentine to maintain the strength of the tooth.
Led by Professor Paul Sharpe, Dickinson Professor of Craniofacial Biology, the results of this study show further evidence that the method could be successfully translated into clinical practice. They discovered that the repair area is highly restricted to pulp cells in the immediate location of the damage and the root pulp is not affected. They also found that the mineral composition of the area of repair was significantly different to that of bone, and more similar to normal dentine.
In addition, they found the drug can activate repair an area of dentine damage up to ten times larger, mimicking the size of small lesions in humans.
Stem cells can be identified in the stroma (connective tissue) of most tissues and organs. These cells provide a source of cells that become activated upon tissue damage to generate differentiated cell types that promote tissue repair. Specific targeting of these resident stem cells has become a major goal for regenerative therapies.
Using the mammalian tooth as an easily accessible model organ, we have developed a novel drug treatment (ReDent) that activates resident stem cells in the tooth pulp to differentiate into the specialised cell type (odontoblasts) that produce reparative dentine. ReDent thus promotes self-repair of teeth following caries removal. ReDent is anticipated to be in clinical trials in the next 12 months. These same principles are also being applied to the development of stem cell-based treatments for periodontal disease.
Teeth are currently replaced using dental implants or prostheses (false teeth). The ultimate goal of regenerative dentistry is to use bioengineering approaches to develop a method that allows a complete new functional tooth to grow in the mouth. The basic proof-of-principle showing this is possible was established several years ago. Our latest progress in this area will be presented and the remaining obstacles discussed.