Nanodiamonds Found to Strengthen Dental Fillings and Reduce Tooth Infection

Diamonds are said to be a girl’s best friend, and it turns out that they could be a pretty strong ally in everyone’s dental health – although don’t go racing to Tiffany’s just yet, as these diamonds are so small, they are invisible to the naked eye.

The strong and robust properties of diamond could be used in dental fillings. (Photo credit: Noel Celis/AFP/Getty Images)

In yet another case of ‘tiny but mighty’, it is time for nanodiamond to take to the (microscope) stage. Often overshadowed in the nanotechnology world by its siblings, carbon nanotubes and graphene, dusty fragments of diamond have now found a use in the world of dentistry.

A root canal procedure is relatively commonplace these days, carried out to remove infected ‘dental pulp’ (blood vessels and nerve tissue). The vacant cavity created by the removal of this matter is then filled with a material known as gutta percha, a biocompatible polyisoprene polymer made from the sap of the Palaquium gutta tree. In theory, removal of infected dental pulp ought to remove all trace of infection; however, this is not always the case, and a patient will often be left with a residual infection that develops over time, resulting in further inflammation in small gaps that the filler cannot fill and possibly result in loss of the tooth. As this cavity has been filled with gutta percha, the infection takes hold deep inside the tooth, with no hope of treating it.

Gutta percha is certainly biocompatible, and its low reactivity in the body is one of the material properties that contributes to its choice as a dental filler. However, in terms of rigidity, it falls down, and it is not the ideal material to keep infections at bay. This is where composite materials save the day.

A composite material is one that contains a range of materials, each of which contributing one or more beneficial material properties to the resultant bulk material. In this case, scientists at UCLA Dentistry in the US incorporated tiny nanodimensional fragments of diamond that were produced as a waste product of diamond mining and refining into this gutta percha, resulting in a more mechanically robust dental filling material. This certainly overcame the challenge of using a filler material that was not very strong, but what about tackling the issue of re-infection from trace infected dental pulp, and the fact that the filler did not efficiently fill the entire cavity?

The UCLA Dentistry researchers decided to combine forces with material scientists and microbiologists to devise a way to pre-load the nanodiamond with a common antibiotic, amoxicillin, which should combat any infection that developed following the root canal procedure. Through close monitoring, it was found that although the filler did not reach every space within the tooth, the rate of infection following treatment was much lower when the pre-loaded nanodiamond was incorporated within the gutta percha.

Over the next two years, the UCLA Dentistry team plans on carrying out further tests with colleagues in other departments and hopes to optimise this material in order to carry out clinical trials that could lead to the widespread use of this filler materials. – Sujata Kundu, Forbes