Bitter mouth after filling may be caused by drug factors, or the patient himself suffers from bile reflux, cholecystitis and other diseases. 1. Drugs:If a patient uses a drug to rinse the mouth when filling a tooth, it may lead to residual drugs in the mouth, so the patient will have a bitter mouth after filling a tooth. 2. Bile reflux:Bile reflux is caused by the pyloric dysfunction of the stomach, and the patient will have excessive gastric acid and weakening of the protective mechanism of the gastric mucosa. When bile reflux, the bile will flow into the mouth, causing the patient to have the symptom of bitter mouth after dental filling. 3. Cholecystitis:Cholecystitis is caused by bile duct obstruction, bile stasis and other factors, the patient’s main symptoms for the epigastric pain severe colic, vomiting, anorexia, constipation, etc., will also lead to the patient’s mouth bitter. As a result, patients can experience a bitter mouth after dental fillings. When patients experience symptoms of a bitter mouth after dental fillings, it may be caused by medications and does not require treatment. If the mouth is bitter due to a long illness, the patient should seek medical attention in time and follow the doctor’s instructions for treatment.