研究故事

The creators of the award-winning NJ toothbrush drew inspiration from high-speed railways and deep knowledge and research on dental and gum diseases to create a flexible toothbrush that can improve oral health by reaching elusive “dead corners” that may be missed by conventional brushes.

Dental and gum diseases are among the most common diseases in the world and they often result from poor oral hygiene. Now, a revolutionary new toothbrush from the Faculty of Dentistry promises to help people do a better job at cleaning their teeth and reaching the “dead corners” where disease can start.

The NJ toothbrush was created by Professor Lijian Jin, Modern Dental Laboratory Professor in Clinical Dental Science and Professor of Periodontology in the Faculty of Dentistry, and Dr T.C. Ng, honorary associate professor in the Faculty, It is able to reach all dental surfaces, including the areas between teeth, the back molars and the niches below the gumline.

The toothbrush is adapted to the curved shape of the dental arches and gums and uses six different types of bristles to allow for automatic expansion and contraction of the brush-head via “auto-coupling” and “joint-hinge” motions, among other features. Moreover, the toothbrush is designed as a “track”, like a high-speed train, to facilitate the correct action of brushing and therefore maximise the control of plaque biofilms.

The patented invention, which won a Gold Award at the 2019 Geneva International Exhibition of Inventions, is based on the unique expertise and research of Dr Ng and Professor Jin. Dr Ng is a local dentist who previously designed precision tools for space exploration, including a sampling tool carried by a European Space Agency flight to Mars in 2003. Professor Jin has conducted major research projects on periodontal diseases and new care strategies and approaches, funded by the Research Grants Council of Hong Kong.