Nanodiamonds could prevent tooth loss after root canals

Los Angeles: Using nanodiamonds to fortify a material employed during root canal could prevent tooth loss, researchers have found.

Nanodiamonds are tiny particles formed as byproducts of diamond refining and mining.

Thousands of times smaller than the width of a human hair, they have been widely explored for use in dentistry, cancer therapy, imaging and regenerative medicine, among other applications.

During a root canal, inflamed dental pulp is removed and the empty space is then filled in with a polymer called gutta percha, which is used in part because it does not react within the body.

But some root canals don't entirely remove the infection, and residual infection after root canals can lead to tooth loss.

In addition, traditional gutta percha has certain shortcomings, including a limited capacity to ward off infection and less-than-optimal rigidity.

To overcome those issues, researchers from the University of California, Los Angeles School of Dentistry developed and tested two types of reinforced gutta percha - one strengthened with nanodiamonds and another strengthened with nanodiamonds that had been pre-loaded with antibiotics.

To evaluate the first type, Sue Vin Kim and Adelheid Nerisa Limansubroto, study co-authors who are UCLA Dentistry students, filled actual teeth from human patients.

Using conventional radiography and micro-computed tomography, they showed that the nanodiamond-enhanced gutta percha could be used to fill the tooth.

Like the traditional formulation, the nanodiamond-enhanced compound did leave small gaps in the canal - where harmful bacteria could grow - but the CT imaging showed that the enhanced material filled the space just as effectively as traditional gutta percha.

"Validating this novel material in teeth extracted from patients serves as a strong foundation for the potential translation of nanodiamond-reinforced gutta percha toward clinical testing," said senior author Dean Ho, co-director of UCLA Dentistry's Jane and Jerry Weintraub Centre for Reconstructive Biotechnology.

In the research's second phase, the scientists tested nanodiamonds that had been loaded with amoxicillin, a broad-spectrum antibiotic used to combat infection.

The drug-reinforced nanodiamonds, when combined with the gutta percha, effectively prevented bacteria growth.

"The nanodiamond-enhanced gutta percha combines many desirable properties into a single platform, including vastly improved mechanical characteristics and the ability to combat bacterial infection following a root canal," said Dong-Keun Lee, a postdoctoral scholar in Ho's lab.

The study was published in the journal ACS Nano.