There are many factors to be considered to clarify this issue. From the doctor’s side, if the decayed material is not removed, the secondary caries will be formed easily, and the surrounding tooth tissue will not be able to provide the retention of the filling if the decayed tissue becomes soft, and the filling material will fall off. Therefore, it is necessary to remove the decayed material. Saliva contamination of the bonding surface will affect the bonding strength, so it should be strictly isolated from moisture. Pay attention to the use of fresh treatment solution to ensure the normal efficacy of the bonding agent, and avoid unused bonding agent being exposed to the air or light source for a long time to change its utility. So the bonding agent should be taken in time. Some areas that are subject to heavy forces or are susceptible to dislodgment by external forces should be prepared with appropriate retention shapes, surface preparation, etc. to increase retention and should be considered for filling treatment or other restorative methods such as full crown restoration with better retention. The above situation can be controlled by experienced doctors during treatment. From the patient’s side: Do you have a mental picture of what to do with the affected tooth after filling? The oral environment is complex, with a wide variety of foods and temperature variations. The filling itself is less susceptible to corrosion, but the teeth around it are not. If you love to eat snacks and sweets, it will be easy to recur decay. If the tooth tissue around the filling becomes soft and decayed, it is not strange that the filling will fall off. Therefore, we should eat less snacks and sweets. In addition, some parts of the filling are heavily burdened by the force, and if the bonding area is small and the filling is relatively large, it is not suitable for chewing hard and tough food. The force of human chewing muscles can reach tens of kilograms, and if it acts on a certain point, it may produce enough consequences to cause the filling to fall off or even cause the tooth to split. Therefore, it is important to eat less hard and tough foods. Therefore, if you want the tooth filling to last longer, the doctor should pay attention to perfect the treatment, and the patient needs to cooperate with the protection use, prevent the secondary caries and eat less hard and tough food. In case of good protection, it is possible to last for decades or even a lifetime. It is not easy to say if the protection is not good. How many years can a good tooth stay intact?