I did make contact with the dentist and it seems it only needed to stay on for 24 hours so I guess I will be OK. Just need to be a bit more careful not to rip the threads out. Does feel a bit strange though - being able to actually feel the teeth and gum again. And it has only been 4 and a bit days! Definitely a cause for going home early today though I think.
Though even that is trickier at the moment as we have been booted off our normal car park (owned by the College) while they do some building work, and instead now have to park down at the waterfront. Only a few more metres to walk and an extra (but very busy) road to cross, but it feels like a lot more and is not as convenient. It should only be for three months, so that will be during the summer and hopefully dry most days at least. Will try harder to remember to bring the brolly in though.