Took Comfrey to vet again tonight and insisted they look again at his mouth as he is still making chewing movements with his mouth and still won't eat hard stuff.
The very very thorough vet (I choose my vets according to needs - I have a 'throw everything medicinal at it and be very thorough' vet', a 'quick check up and basic op. in an emergency vet', and a 'knowledgeable and chatty and friendly in for the longer term but not so keen on intervention straight away' vet!! all at the same place!!).
The thorough vet looked in his mouth again - poor soul must be getting a mouth complex - and found he had some gum discharge and a pale gum area now and some sharp teeth again front and rear even though he supposedly had it all done only 10 days ago.
He is now booked in for another dental next week - I strongly suspect that the last dental (done by vet no.2 on my list) just wasn't thorough enough in first place - although not helped by the fact that he hasn't eaten solids since it was done..
Poor Comfrey!!!