Teeth are the gateway to health. Missing teeth not only affect the function of chewing, but also affect the aesthetics, so timely restoration is necessary. There are two types of dentures: one is fixed and the other is removable. So, which restoration method to choose after the loss of teeth? These two types of dentures have their own advantages and disadvantages, the choice is based on the number of missing teeth in the mouth and the health of existing teeth to decide. Fixed denture: In medical terms, it is called a fixed denture or fixed bridge. It is the use of missing teeth adjacent to the good teeth on both sides of the gap to fix the denture on it. It is like building a bridge that must have a solid foundation and cannot be removed and worn by the patient himself. This type of denture is manufactured by first grinding away a portion of the abutment teeth (the teeth that serve as the foundation) at each end, then creating a metal crown that is placed over the abutment teeth, and then using another metal rod to connect the two ends, with plastic teeth in between. Its advantages are small size, comfort, no foreign body sensation, easy to get used to after fitting into the mouth; chewing function is greater than that of removable dentures. The disadvantage is that the condition of the abutment teeth at both ends should be good, and in the preparation, many abutment teeth have to be grinded away, which requires higher conditions for the preparation of the doctor, and some of these teeth made by some wandering doctors are definitely not up to the scientific standard. Some people often do not welcome fixed dentures because of the pain caused by grinding, in addition, fixed teeth have a metal crown set is not beautiful, not too many lost teeth, to 1 to 2 missing teeth is appropriate. The movable denture: is the use of plastic as a base, relying on mucosa, bone tissue for support, relying on the retention of the denture and the retention of the base, can be freely taken to wear a prosthesis, so called movable denture. It consists of a denture on a base and a flexible metal ring. The chewing pressure is not entirely borne by the two neighboring teeth, but also by the gums and alveolar bone in the missing teeth. Therefore, a removable denture can be fitted even if the adjacent teeth are not very strong at both ends. Its advantages are that it is easier to operate, less tooth grinding, better aesthetics than metal crowns, easier for patients to accept, and the brackets can be taken off and washed, which is good for oral hygiene. The “living tooth” has a wide range of adaptation and can restore more missing teeth, from one missing tooth to several or even the whole mouth. The disadvantage is that it takes a long time to get used to the implant. Another method is the implicit denture, which does not use metal rings, but uses a special plastic with elasticity and gum color as a retainer, which has also been carried out in some areas of China in recent years. In short, the general tooth loss must be installed after the denture, its purpose is mainly to restore the chewing function and physiological function, to avoid the displacement of other teeth, as for the care of aesthetic, is still secondary. To achieve these purposes, there must be a scientific choice of mounting method, must be based on the specific circumstances of the patient, in order to determine the mounting of fixed dentures or movable dentures.