It is necessary to fill the teeth of a 5 year old child, and it is recommended to repair the decay of the teeth once it occurs, especially the decay of the teeth other than the incisors. Although 5-year-old children’s mouth are milk teeth, but the back of the milk teeth from the replacement of a very long time, once the caries of milk teeth caused by apical inflammation, there is a possibility of causing damage to the permanent tooth embryo below, called Turner’s tooth. Due to the texture of the milk teeth, once the caries spreads relatively quickly, it will eventually lead to the early loss of milk teeth, which will cause a series of problems such as irregularities in the eruption of the permanent teeth and crowding of the teeth, so it is also recommended to repair caries in the milk teeth as soon as possible.