We advise you to eat as usual before the dental treatment. It is not advisable to undergo treatment neither on a full nor on an empty stomach.
Take all the medicines you regularly do before the treatment, except your medical advisor suggested otherwise. These cases are special (e.g. taking anticoagulants) so they always require preliminary consultation and they have to be documented: you should never act based on your own decision.
After the treatment we often discourage you from eating until the effect of the anaesthetic has gone. We would like our patients with diabetes, to pay attention in this respect on harmonizing the time of treatment with their daily routines.