If there is residue: the residue of sweet food in the mouth can produce acid under the action of bacterial decomposition, brush the teeth in time, rinse with chlorhexidine and other solutions or apply a lot of saline to reduce the retention of food residue and soft scale and dilute the acidic products in the mouth. 2, there is gap: the gap between the teeth is large and the food fiber is often embedded, you can apply flush 3.Have cavity: When there is deep cavity in the crown of the tooth and the embedded food soft scale causes sour smell, you can remove the decaying matter, apply alcohol disinfection and use composite resin etc. to fill it. 4.Gastric acid reflux: When sweet food causes large secretion of gastric acid and gastric acid reflux and stimulates the oral mucosa, systemic examination should be conducted and timely treatment Gastric ulcer, duodenal ulcer and other digestive system diseases.