Ok, so what exactly is a "dentist's chair" and why would it be banned? Good question. Does it mean that a way to ensure good oral hygiene has been found that avoids visits to the dentist? We wish. No, the "dentist's chair" that has been banned by the British government is something else. In the United Kingdom binge drinking is a big problem; at the pub's they have "boozy contests" like the "dentist's chair made famous by the celebrations of footballer Paul Gascoigne at Euro '96, where drinks are poured directly into the mouth by others." [1] They also have promotions of all you can drink for 10 pounds, which are also being banned.
It is great that the British government is taking action to protect its citizens from their own foolishness.