Needle-free dental anaesthesia

29 September 2022

Researchers are literally taking the pain out of visits to the dentist after the successful creation and pilot trial of a needle-free device for dental anaesthesia for teeth extractions.

A collaboration between the University of Otago, the University of Auckland, and the Auckland University of Technology, the device differs from other needle-free dental jet injectors in that it is driven by a silent motor and is specifically designed for dental work.

Eight patients who all needed the removal of top teeth as part of their treatment plan were included in the trial. All participants received both the traditional needle and the needle-free injection device.

The needle-free anaesthesia was the preferred technique by all of the participants at all stages, and six of the eight reported a pain-free extraction with the needle-free delivery. In two cases further anaesthetic was required by the traditional needle technique.

Professor Paul Brunton, who undertook the study, published in the Journal of Dentistry, while at the University of Otago Faculty of Dentistry, says fear of needles is a significant barrier to people going to the dentist.

“Dental anxiety or fear of dental procedures is a significant barrier to accessing regular dental care, affecting about nine per cent of the global population. Dental anxiety and needle phobia have contributed to more patients avoiding dental treatment and missing regular check-ups, generating poor oral health outcomes and associated impacts on general health.”

Such anxiety often arises from negative past experiences in the dental chair, with needle anaesthesia being one of the common generators of the fear, he says, “Patients often fear more the sight of a needle during local anaesthetic delivery than the treatment itself.”

Of the eight participants in the study, five were not considered to have dental anxiety, two had mild dental anxiety and one was classified as having high dental anxiety.

The patients were followed for seven days after the treatment to gather further feedback on the levels of discomfort and preferred technique, but also to check on the healing of the sockets and bleeding of the injection site.  In all cases healing was “uneventful” irrespective of the technique used.

“Even though this was just a proof of concept trial, this device certainly could reduce or eliminate anxiety due to needle phobia,” Paul says.

While the results of this study are encouraging, a larger clinical trial is the next step to validate the technique and investigate whether it can be used for other dental treatments that require local anaesthesia.

Professor Andrew Taberner, of the Auckland Bioengineering Institute, says while there are other jet injectors on the market, they tend to be lightly modified injectors for insulin or other drugs, and not specifically redesigned for dentistry, as is the case here.

“All other dental jet injectors use springs or compressed gas to power the injection; these have the drawback of noise, and impact, when the drug is delivered. Moreover, this study was the first time I have seen anyone jet-inject through a slender wand that is a bit like a three-in-one tool, and can easily be introduced into the back of the mouth.”