Some patients don't have long after filling their teeth, and the filling materials fall off. What is the reason? How to solve it? The following stomatologists from Liang Ya Stomatology Department of Beijing Medical University will give you detailed answers. According to dental experts in Liang Ya, there are several main reasons for material loss after filling: 1, severe caries, loss of retention: severe caries generally refers to residual crown or root: the retention of residual crown or root is better than that of residual root. Generally speaking, the residual crown or root has no normal retention, and it is the easiest to loosen the filler. Attention should be paid to the retention of residual crowns or roots before restoration. The specific method is to use root canal retention and insert root canal nails to increase retention. 2. Broken teeth: Broken teeth are more common in teeth with close contact with fillings, and the chewing pressure is greater than other teeth, which is medically called traumatic occlusion. The internal injury of dental crown is characterized by the fracture of dental crown, especially the adjacent cavity, which causes the fracture of one dental crown and filling material. Metal shell crown technology is often used to repair and solve problems. 3, tooth fracture: tooth fracture mostly occurs in dead pulp teeth. Because dead pulp teeth are brittle, resistant to pressure drop and easy to break. Measures to prevent broken pulp teeth after filling: reducing occlusion; Crown repair technology can also be used to prevent damage. 4. Secondary caries makes the filling material loose and fall off: the caries that occurs at the edge of the filling body or under the filling body is called secondary caries. The reasons for the loosening and shedding of filling materials caused by secondary caries are as follows: (1) The cavity wall tissue is weak: the weak tooth tissue may be crushed and food impaction may occur. This is due to the weakness of the tunnel wall and the pressure difference. In addition, the lack of undercoat will also cause the wall of the cave to be weak, because there is a lack of dentin lining under the enamel, and the compression resistance will decrease. ⑵ Oral saliva pollutes tooth cavities: Some materials become soft and dissolve immediately when they meet water, such as zinc phosphate cement powder, which may lead to the material not being close to teeth. In order to prevent oral saliva pollution, it is usually necessary to isolate saliva and dry the mouth with an air gun. (3) Dissolution of substances at the edge of the cave wall: refers to substances attached to the edge of the cave wall, especially to the bottom of the mouth of the cave or the neck of the secondary cave, such as zinc oxide clove ointment, zinc phosphate cement, etc., which can be dissolved by saliva, and a gap will appear after dissolution, causing caries. In fact, it is not difficult to check whether the bottom hole is attached to the bottom material. Scoop is generally used to remove the material at the bottom of the hole. more