Your crowns are not the reason for this.
DRYNESS IN MOUTH CAN BE COZ OF MOUTH BREATHING.
It can be due to meds also but whether you are one among them can be verified by taking your medicine history.
Use Mouth wash(NON Alcohol Based) for one week morning evening.
Usually such a symptom I see owing to a medicine or hormonal changes.
Next Steps
Give it sometime and meanwhile use mouthwash(not alcohol based)
Health Tips
Avoid Mouth Breathing....