U of T researcher develops nanosystem that promotes regeneration after root canals

A novel nanosystem developed by Anil Kishen, a professor in the University of Toronto’s Faculty of Dentistry, shows promising results in promoting healing and regeneration by host tissues following root canals.

Kishen’s research was published recently in the medical journal Nanomedicine: Nanotechology, Biology and Medicine.

The current treatment for root canals focuses on reducing bacterial loads. After instrumentation and irrigation, however, the canals of the tooth are filled with synthetic materials – with the possibility that the infecting bacteria colonies are not fully eliminated. That can leave the tooth susceptible to persistent infections.

“What we believe is that current treatment aims to eliminate bacteria. But it doesn’t influence the body to heal,” says Kishen, who adds that a new, more biologically based approach is key to improving root canal treatment outcomes.

After root canal preparation, Kishen’s system involves packing the bioactive nanosystem into the apical (tip) portion of the root. The core of the system is synthesized with a naturally derived chitosan, which is derived from the shells of shrimps and other crustaceans, while the shell derives from calcium alginate base – compounds known to be safe for humans.

Pre-loaded into this shell system are two molecules that promote stem cell and tissue growth, transforming growth factor (TGF-B) and dexamethasone (Dex). Through the carefully timed release of these molecules through the core shell, they attract host immune cells from nearby areas, jumpstarting the body’s own tissue repair and regrowth processes.

Carried out in guinea pig models, the study illustrated enhanced cell migration and stem cell differentiation, according to the study authors.

The researchers hope to soon carry out clinical evaluations using their novel treatment paradigm, a move made easier due to the organic components of their base and biological basis of this treatment.

“We think there can be a more predictable mode of healing,” says Kishen.

Approximately 15.1 million root canals are performed in the U.S. each year. Yet despite improvements in the field, the failure rate for root canal interventions hovers between five and 22 per cent. Root canals are also more prevalent in the elderly, making it a health burden that rests unequally with this economically vulnerable and growing population.

Kishen has previously applied his organically derived nanosystem technology in the creation of a novel tooth sensitivity product, BioSchell, which was commercialized in 2016.