Toothbrush Reaches All Tooth Surfaces for More Effective Cleaning

Dentistry Today


Unlike other toothbrushes, the NJ Toothbrush simultaneously reaches the entire tooth, including the interdental, retromolar, and sub-gumline niches, according to its developers at the University of Hong Kong (HKU) Faculty of Dentistry.

Honorary associate professor Dr. TC Ng and periodontology professor Dr. LJ Lin used precise computer mapping of six types of purpose-built bristle bundles angled with specific lengths and diameters that target all dental surfaces and niches.

For example, the brush’s soft bristles target soft supporting tissue, while its hard bristles target hard dental morphologies. Also, specific sub-gumline bristles enable users to clean plaque under the gumline.  

Ultrasonic vibration creates micro-circular motion on tooth surfaces by each bristle. With thousands of bristles, millions of these micro-actions would then cover the full surface areas of the teeth and sub-gumlines. 

The design is based on users coupling the toothbrush along the dental arch rail track, going from one end of the mouth to the other without stopping. As it moves along the dental arches, the brush head moves freely and automatically from one side to the other.

The brush head also automatically fits the lingual-palatal and buccal-labial surfaces of the upper and lower canines and incisors, easily reaching all surfaces of the front and posterior teeth at the same time.

Ng also designs precision tools for space exploration, such as the sampling tool carried by the European Space Agency’s Beagle 2, which landed on Mars in 2003. Jin’s research has focused on periodontal etiopathogenesis and novel care strategies.

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