The caries of milk teeth at the age of 6 weeks, because the age of 6 weeks is exactly the period of alternation of milk and permanent teeth of children. At this time, we have to see the tooth position of the milk tooth, if it is the caries of the first 4 teeth, we have to determine whether it is a permanent tooth. If it is confirmed that it is a milk tooth caries, we can consider extracting this milk tooth directly, provided that we take dental film to see the situation that the permanent tooth underneath is about to erupt, then we can extract the milk tooth and wait for the permanent tooth to erupt. In case of the usual 3rd, 4th and 5th teeth, the decayed teeth will be removed. Since it takes some time to replace these three baby teeth, they may need to serve in the mouth for 3-4 years, so it is recommended to decay and fill the baby teeth at this time.