Implant Impression Techniques using Different Materials and Methods: A Review

Dental implants have emerged as the treatment of choice for restoring missing teeth in situations that require functional and aesthetic replacements. Reproduction of the position and orientation of intraoral implants by means of an accurate impression in the definitive cast is the first step in achieving a passively fitting multi-implant supported prosthesis, to decrease the mechanical and biological complication of the prosthesis. The accuracy of the impression making procedure in the usage of osseointegrated implants used for the rehabilitation of fully and partially edentulous patients is a very important factor for the long-term success of dental implants. It has been reported that the precision of implant impressions is affected by various factors such as impression materials, impression technique, splinting of impression posts, impression level and depth, as well as the angle of the implants. Also, the incompatibility between implant and prosthesis, which may occur as a result of an incorrect impression, may cause problems such as screw loosening, screw fracture, loss of osseointegration and even implant fracture. In recent research, there are many articles and reviews about implant impressions. Although the authors found consistent results in many studies, there are differences of opinion on some issues. In general, polyether and additional type silicones were found to be successful in the conventional impression technique. Digital impression technique, on the other hand, has been found as successful as conventional measurement techniques in some studies. Controversial results have been obtained about the number of implants and their angulation. In general, the direct open tray splinted impression method is recommended for four or more implants, while there was no difference between the direct or indirect method for three or less implants.