(1) Multiple in vitro studies reported insufficient accuracy of intraoral scanners (IOSs) for complete-arch multiple implant impression. The aim of the study is to analyze the precision of three IOSs, PIC dental (Pic dental, Iditec North West SL), TRIOS 3 (3Shape), and True Definition (Midmark Corporation) and the influence of several factors in the edentulous complete maxillary and mandibular arch. (2) A fully edentulous patient with eight implants in the maxillary and in the mandibular jaw was selected. Five impressions were taken per system and arch. A suprastructure was designed on each digital working cast. The precision was analyzed comparing each of the 28 distances and seven relative angulations of the abutments of all the designed suprastructures. The descriptive statistics, the Student’s t-test, and the ANOVA test were used to analyze the data (α = 0.05). (3) Significant differences were observed when comparing the IOSs in some of the distances and angulations. (4) The increase in the distance between implants affected the precision of T and TD but not the PIC system. The type of arch did not affect the PIC precision, but the T and TD systems performed worse in the mandibular arch. The system with the best precision was the PIC, followed by TD, and then T.

The aims of this in vivo study were to determine which implant impression technique has the best in-mouth precision and to analyse whether the maxillary or mandibular position of the implants and the increase in the interimplant distance affect the precision. A fully edentulous patient rehabilitated with 8 implants in each arch was included in this in vivo study. Five impressions per technique and arch were obtained using 6 impression techniques: closed tray (IT), unsplinted direct technique (UDT), acrylic resin-splinted direct technique (ASDT), metal-splinted direct technique (MSDT), stereophotogrammetry (PIC system), and intraoral scanning (Trios). Precision was evaluated by comparing 28 Euclidean interabutment distances per impression. A threshold of 75 μm was used as a reference value based on previously published implant misfit studies. Within the limitations of this study, the PIC system showed the highest precision among the evaluated techniques with 95% of the values <75 μm for the mandibular arch and 99% for the maxillary arch. The IT technique did not result in differences in the precision between the maxillary and the mandibular arches (P = .663); the other techniques showed statistically significant differences between the maxillary and the mandibular positions of the implants (P < .001). Significant differences were observed when comparing the precision of the 6 techniques, with the PIC system tending to show the highest precision within the limitations of this study. Statistically significant differences were also obtained between the maxillary arch and the mandibular arch within each technique and the precision decreased as the interimplant distance increased, particularly for the T technique.

Achieving a passive and accurate fit in full-arch implant-supported prostheses remains a significant challenge in digital dentistry. Intraoral scan bodies (ISBs) are essential components for transferring implant positions digitally. However, variations in ISB material, geometry, and height may influence the accuracy and precision of intraoral scans. This study aimed to evaluate how different ISB designs affect the trueness and precision of digital impressions in a completely edentulous maxillary arch with multiple implants. An in vitro model with 8 implants was scanned using the Primescan intraoral scanner. Five ISB configurations were tested: four from different manufacturers (ELOS, GT Medical, ZIACOM, and 3Shape) and a fifth mixed group with alternating ISBs. A coordinate measuring machine (CMM) was used as the reference standard. Accuracy was assessed through linear (Euclidean distance) and angular (relative angulation) measurements. Statistical comparisons included ANOVA, pairwise analysis, and multivariate regression. Significant differences were found among ISBs in both trueness and precision. ZIACOM showed the best precision overall, particularly in repeated linear (21 ± 16 μm) and angular measurements (0.102± 0.081 degrees), while ELOS displayed the lowest deviation in linear distance (40 ± 33 μm). The mixed ISB group yielded the highest variability and the most extreme errors. Although mean values were within clinically acceptable limits, maximum deviations reached 223 µm and 1.2°, potentially compromising passive fit. ISB selection significantly affects the accuracy and reproducibility of intraoral scans in full-arch implant scenarios. Using a consistent ISB system is recommended, as mixing components from different manufacturers may increase variability and compromise the reliability of digital impressions in complex rehabilitations.