Dental implant is a kind of edentulous restoration which is based on the lower structure implanted into bone tissue to support and retain the upper tooth prosthesis. It includes two parts: the lower supporting implant and the upper dental prosthesis, which are mainly for the treatment of tooth defect and missing. The cylindrical and/or tapered post is typically made of titanium, and serves as a substitute for the tooth root.
Dental implants are available in a variety of sizes and heights, including standard and narrow (mini). The most commonly used type of implant is the endosteal implant, which is a small screw-, cylinder- or plate-shaped implant placed in the mandible. Subperiosteal implants are placed under the gingiva on or above the mandible, in patients with shallow mandibles or for those who prefer not to undergo rebuilding procedures. The implant system is usually classified according to the material, shape structure, surface structure and connection mode of the implant. The clinical practice of dental implant makes the contemporary dental implant materials and implant morphology tend to be unitary. The implants are mainly made of grade 4 commercial pure titanium. The screw column and root implants have been widely accepted in the world. It has been proved that the surface area and osseointegration of the implant can be increased by the moderate roughness of the surface structure. Therefore, the current clinical implant systems are generally rough surfaces obtained by various surface treatments. The implant and the prosthesis above it are connected by a certain structure, mainly divided into external connection and internal connection.
