The life span of different types of dentures varies. Generally speaking, dentures are divided into three types: fixed dentures, movable partial dentures and full dentures. Fixed dentures can generally be used for a long time, and if there is no major loss or discomfort, they generally do not need to be replaced. However, in special cases, their life span can be rapidly shortened. For example, porcelain teeth are easily damaged by fracturing when they are subjected to excessive force during chewing. In addition, if the individual teeth adjacent to the fixed dentures are decayed or have periodontitis and loose teeth, then the life of this denture will also be shortened. The general life of removable partial dentures is 3-5 years, and the life of full dentures is 5-7 years, and if you pay attention to maintenance and care when using them, the life will be longer. Because full dentures are made of plastic and a mixture of plastic and metal materials, so they are not wear-resistant. Li Yifei, Department of Stomatology, People’s Hospital of Tibet Autonomous Region If the movable dentures are not suitable, or long-term use, lack of scientific maintenance and maintenance, will lead to a decline in the function of dentures. Patients have to increase the strength of the teeth when biting, which directly leads to excessive friction between the dentures and the gum mucosa, and is very likely to cause traumatic ulcers. If these ulcers do not heal, they will eventually lead to the formation of oral mucosal cancer, which is a very serious consequence. In addition, after the extraction of the full mouth teeth, the alveolar bone head will be progressively absorbed, and a large gap will be created between the abutment of the full denture and the oral mucosa, which will reduce the degree of fit and easily fall off, affecting chewing, at this time, you should consider replacing the full denture.