Sir, the last heretic to be burnt at the stake in Britain was in 1612. Today punishments are more climate-change friendly, but still can result in erasure from the dental register. Still, I would like to dissent from established orthodoxy.

With regard to the article 'Dam it - it's easy!' - or is it?,1 it seems to suggest that there are no contra-indications or qualifications to its universal use. I beg to differ.

I have worked for many years treating phobics under IV sedation. I also worked for many years (outside the UK) as an anaesthetist. I remember being a lonely voice at SAAD meetings advocating a four-hour fast and now note that the profession is more in line with established anaesthetic practice.

Accepting that sedation is a continuum and doesn't divide strictly into classical Guedel planes, I would like to put forward the view that there are problems when using a rubber dam in combination with IV sedation.

Saliva pooling is hidden behind the dam and so cannot be visualised and suctioned directly. Second in the event of needing a rapid response to airway obstruction, precious time would be lost removing the paraphernalia of clamps. Even with endodontics, I think balancing risk against risk, it would be better to control against misplaced files with floss ties in preference to dam. Proponents of rubber dam should recognise that it is not a universal panacea and I hope that anaesthetists reading this will add their voice to my concerns.