Sir, as part of recent training in the use of computer controlled anaesthetic delivery techniques it was agreed that participants could trial this for themselves. As a consequence of this, I felt compelled to highlight a personal experience using this widely available commercial system.

The device is designed to target a wide audience, especially dental phobic patients and patients in whom regional blocks are medically contraindicated. The equipment can deliver a slow intraligamentary injection, giving audio and visual feedback to the operator, to ensure correct location.

Delivery itself is reasonably comfortable if not brief – instructions suggest giving over the course of approximately two to three minutes. Once anaesthetised, having only a single lower tooth numb, with limited soft tissue, anaesthesia is a curiosity. Even more curious is the sensation of a tooth that feels raised into supraocclusion. Indeed, if the anaesthetic has been delivered correctly, hydrostatic forces will have elevated the tooth in the socket, a feeling that lasted until the next day.

Over the hour following delivery, all which had experienced the injection felt a sensation that was only possible to describe as 'itching'. This sensation lasted for about an hour after symptomatic onset, and out of all postoperative sensations, was the most uncomfortable.

As someone who has experienced palatal injections, ID blocks and tooth extractions, my expectations of this system were fairly high. Having had the experience (admittedly only one) I can understand that patients are more likely to accept the equipment over traditional syringes. However, I struggle to see a dental phobic or paediatric patient tolerating the potential post-operative effects well. Especially as most occur after a patient would have left the surgery, and may not have been warned about.

Thought must also be given to the operator who may be unable to correctly contour restorations as the tooth is artificially raised at the time of finish.

Dr Veerkamp highlighted in a recent commentary1 that there does exist a potential for such equipment. However, the specific situations in which this method provides benefits is in need of highlighting to operators. I am looking forward to seeing the progress of 'pain free' anaesthesia over a working lifetime and I wonder whether this type of system will have a place, or whether conventional techniques will withstand the test of time.