The salivary flow measurement was performed by having patients chew an extra-soft silicone device. Samples were obtained with the patient sitting comfortably with the head slightly tilted forward. Patients were told to chew the silicone device as it was tied to a 25cm dental floss in order to prevent accidental swallowing. All patients who used dental prostheses were required to wear them during measurement. The saliva produced during a period of 5 minutes was collected and measured in a container graduated at 0.05ml. The volume of salivary flow was calculated in ml/min (millimiter per minute). The patient was instructed not to swallow any amount of saliva that was being produced. Additionally, the patient should keep the body tilted forward in order to avoid saliva swallowing.