There is no worm inside the cavity, the formation of tooth decay is related to the presence of bacterial germs. After the formation of tooth decay, resin filling is usually performed after grinding away the decayed tooth tissue using specialized instruments while keeping the mouth clean. Tooth decay is medically known as dental caries, is due to poor oral hygiene and sanitation, the accumulation of food debris for the bacteria to provide nutrients, under the action of time and the teeth react, so that the teeth rot, generally using specialized instruments to grind away the decayed dental tissues after the resin filling, you can stop caries continue to progress to the depths. However, if pulpitis has already occurred, root canal treatment is also required before resin filling can be performed. The formation of tooth decay is closely related to oral hygiene and cleanliness, which requires effective brushing, morning and evening brushing, careful cleaning of the adjacent surfaces of the teeth, and removal of food debris and soft tartar from the surface of the teeth. For more information, please consult a medical professional.