[Prevention and management of mechanical complications in implant supported fixed prostheses]

Mechanical complications of implant-supported prostheses, which result from stress or mechanical strength and have presented a high incidence, include a number of types such as implant fracture, screw loosening or fracture, abutment fracture, veneer fracture, framework fracture and loss of retention of the prostheses. Possible influencing factors of these complications could be the implant design, diameter and number of the implant, implant position, screw or cement retained superstructure, cantilever, oral parafunction, crown-implant ratio, precision of fabrication and material of the prostheses. Comprehensive consideration of treatment plan, surgery, fabrication and try-in of the prostheses, use and maintenance of the patients is essential in prevention and management of the mechanical complications of implant-supported fixed prostheses.