Sir, the recent worldwide shortage in dental local anaesthetic cartridges has prompted me to raise the question of our 2.2 ml local anaesthetic cartridges sup plied to the UK market.

Can anybody give me one good scientific reason why we should use 2.2 ml local anaesthetic cartridges compared to 1.7 ml cartridges that are used throughout the rest of the world? Surely it is our duty as clinicians, when injecting any type of drug into our patients, to administer the minimum amount of drug that will achieve the desired outcome? 1.7 ml of local anaesthetic solution is very effective in achieving adequate levels of anaesthesia for our dental procedures. Why therefore, do we persist in giving 2.2 ml of local anaesthetic in the UK? Perhaps it is nothing more than, traditionally, our dental local anaesthetic syringes have accepted the larger size cartridge.

Surely, the present crisis in local anaesthetic manufacturing worldwide, should prompt us to dispense, once and for all, with 2.2 ml cartridges and fall in line with the rest of the world and use the 1.7 ml cartridge size?