Accuracy of digital and conventional implant impression techniques - A comparative clinical study

Abstract

Because an incorrect transfer of 3D implant sites might result in an ill-fitting prosthetic replacement with problems including peri implantitis, screw loosening, screw fracture, prosthesis or implant fracture, precise implant impressions are crucial. Therefore, it is of interest to evaluate and compare the accuracy of digital and conventional implant impression techniques in partially edentulous cases with two posterior implants. Fifteen patients underwent both conventional polyvinyl siloxane impressions and digital intraoral scanning and the resulting master models were analyzed using laboratory scanning and three-dimensional reverse engineering software to assess inter-implant distance, angulation, rotation and surface mismatch. There was statistically insignificant differences were noted between the two impression techniques for inter-implant distance, angulation, rotation, or distal implant surface mismatch, whereas a significantly greater mesial implant surface mismatch was found with the digital impression technique (p = 0.02484). Strong positive correlations were observed between the two techniques for distance, angulation and rotation, while a moderate positive correlation was noted for mesial and distal implant surface mismatch. Thus, digital impressions showed accuracy comparable to conventional impressions for short-span posterior implant restorations and can be considered a reliable alternative for routine clinical application.