If one or two teeth are missing, several ways of restoration can be used, such as dental implants, fixed bridges, bonded bridges, and removable dentures. Dental implant: It is a surgical procedure to place an artificial tooth root (usually pure titanium material) in the alveolar bone in a missing tooth area without a root, and then restore it on the artificial root after it has been well integrated with the bone tissue. It is possible to restore a single tooth, multiple teeth, or even a full mouth without teeth. The advantage of implants is that they can be placed where teeth are missing, without destroying adjacent teeth. Because they are fixed, they are comfortable and efficient in chewing. The disadvantage is that surgery is required, it is more expensive, it takes longer (it may take several months) and sometimes bone implants are needed first. Fixed bridge: The adjacent teeth (called abutment teeth) are first ground down to the desired shape and then restored with a full crown (braces) or partial crowns to restore the shape of the adjacent teeth and simultaneously restore the missing area with a one-piece cast bridge. The advantages are that the shape is close to the natural tooth, comfortable, no daily removal, and high chewing efficiency. The disadvantage is that it destroys the adjacent teeth and is more expensive. However, it is ideal if the adjacent teeth are incomplete or if they need to be protected by a full crown. Bonded bridge: It is a fixed restoration in which the bridge to restore the missing tooth area is bonded to the adjacent teeth on both sides by means of a resin cement. The advantage is that the amount of tooth grinding is small, and because it is a fixed restoration, it is comfortable and does not need to be removed, similar to a regular fixed bridge. The disadvantage is that a certain amount of adjacent teeth still need to be removed and the long-term effect depends on the bonding effect, which may lead to debonding. Removable denture: A removable denture that is fixed to the surrounding adjacent abutment teeth by means of a metal hook (called a retainer in technical terms). Advantages include minimal tooth grinding, relatively simple fabrication process, low cost, and can be used as a reversible restoration or transitional denture. The disadvantages are that they are large, have a thicker base to restore soft tissues such as gums and to help retain and stabilize them. Sometimes one side of the missing tooth has to be fixed by the other side of the tooth. It requires a period of adaptation when first worn, needs to be taken off and cleaned after daily meals, has a micro-movement, chewing efficiency is low, the metal ring is exposed and affects the aesthetics, and the accumulation of food scale caused by not cleaning under the abutment or around the ring in time will easily cause caries of adjacent teeth. The specific method of restoration depends on whether the neighboring teeth need full crown restoration. If it is needed, then fixed bridge is the first choice; if the neighboring teeth are intact and healthy, then movable denture, implant denture, or bonded denture is recommended; if there are problems such as small gap, tight bite, or malposition of neighboring teeth in the missing tooth area, then orthodontic orthodontic restoration may be needed first or movable denture can be used directly; if the number of missing teeth is more than two for the back teeth and more than four for the front teeth, or the condition of the neighboring abutment teeth is not good, then the removable denture is the main choice. The implant restoration is also an ideal restoration method.