Your dog's teeth will be cleaned under general anesthesia so as Patti mentioned they usually run blood work in advance of the cleaning. Some vets run the blood work that day and some do it before. The dog is then placed under general anesthesia. The vet then examines the teeth and gums and checks for pocketing and any other signs of disease. If the vet has dental xray equipment, they will take xrays to see the tooth and bone below the gum line. Any diseased teeth will be removed and if needed stitches placed. The veterinary technician (usually) then cleans the teeth dental instruments and polishes them. The oral cavity is cleaned out. The dog is woken up and sent to recovery until alert enough to come home. Depending on the dog and the doctor and the procedure you may go home with antibiotics and pain meds. Your dog comes home with fresh breath and clean teeth.
Good luck
