Conventional versus digital impression accuracy in maxillary and mandibular all-on-4 prostheses: An in vitro study

Abstract

Accurate impression making is essential for achieving passive fit and long-term success of All-on-4 implant-supported prostheses, and this study compared the accuracy of conventional and digital impression techniques for maxillary and mandibular All-on-4 restorations. Sixty impressions were allocated into four groups (n = 15 each): maxillary digital, maxillary conventional, mandibular digital, and mandibular conventional; conventional impressions were made using an open-tray splinted elastomeric technique, whereas digital impressions were obtained with the Medit i600 intraoral scanner and analyzed using Medit Design 2.1.4 software. Mean deviations ranged from −0.004 to 0.154 mm in the maxilla and from −0.069 to 0.225 mm in the mandible, with no significant difference in overall trueness between arches (p > 0.05). Digital impressions showed accuracy comparable to conventional impressions, with greater reproducibility in the maxillary arch and slightly higher variability in the mandibular arch. Thus, data shows the Medit i600 digital workflow proved to be a reliable alternative to conventional impression techniques for complete-arch All-on-4 implant-supported prostheses.