Technical complications on implant restorations exist since the beginning of implant-prosthetic rehabilitation of patients. One of the most common complications we can expect isthe abutment screw loosening. This complication is not catastrophic, but if it reappears after reparation, it may have a negative impact on the outcome of therapy and patient’s satisfaction. Type of connection between the implant and the prosthesis, the patient’s parafunctional habits, and the type of prosthesis are the factors which affect the occurrence of prosthetic complications. Depending on the type of connection, first developed systems were with an external hexagon connection, which was changed to internal hexagon and conical connections, because of short connection and frequent loosening of the fixation screw of external systems. Biological, technical and aesthetic factors are important for the selection of method for fixation of fixed dental prosthesis (cement or screw retention). Loosening of the fixation screw occurs more often in the implant prosthetic constructions which are fixed with the screw, than in cemented ones. Fixation screw repair is very simple and predictable if patient comes immediately after the appearance of first signs of looseness. Restorations which are cement retained are less demanding, the cost of making this type of construction is lower, and technicians and dentists are usually more skilled with it. If the fixation screw loosens (cement retained implantprosthetic restoration), the repair of such restoration is demanding and with an unpredictable outcome, and it is often necessary to repeat this prosthetic restoration (from the impression phase).