Can a temporary crown cause dry mouth, nasty coating on teeth around it & bad breath?

I have had the crown only a week and after brushing my teeth before bed, I wake up with a nasty mouth in the night. It seems to get more pronounced as the days go by. I feel a coating on my teeth and gums on the cheek side. I have maintained daily brushing, routine dental cleanings, and this is not my first crown. I did not have this problem with the others. I am 61 years old, have problems with cracked teeth (reason for crowns), and am lactose intolerant.