How long it will take for the loose teeth to fall out cannot be generalized, it needs to be determined according to the specific situation, it may fall out naturally during chewing, or it may need to be removed artificially, or it may be delayed after treatment. 1. If a child is in the tooth replacement period, and the roots of the milk teeth are very loose when the teeth are replaced, the milk teeth may fall out naturally in the process of chewing. If the force of permanent teeth eruption is insufficient, the milk teeth may not fall out naturally and may need to be removed in hospital. 2. If the loosening of teeth is caused by periodontitis, if the periodontitis is serious and the loosening of teeth is serious, the teeth may fall out in a short period of time. If timely treatment is given to reduce the degree of loosening of teeth, the loss of teeth can be delayed. 3. Loose teeth caused by trauma, through timely loosening of teeth fixed, generally can be better recovery, reduce the risk of loss; but if a serious root fracture occurs, the affected teeth generally can not be retained. When the teeth are very loose, it is recommended to consult a doctor in time for examination to clarify the cause of the disease and receive appropriate treatment.