Trueness of extraoral photogrammetry, intraoral photogrammetry and direct intraoral scanning in the full-arch digital implant impression: a comparative in vitro study
Francesco Mangano, Henriette Lerner, Gabriele Valle, Francesco Biaggini, Carlo Mangano, A.M. Dybov
Abstract
OBJECTIVE: To compare the trueness of extraoral photogrammetry (EPG), intraoral photogrammetry (IPG), and four intraoral scanners (IOSs) in capturing a completely edentulous model with six implant analogs. METHODS: A type IV plaster master model containing six implant analogs was digitized using a coordinate measuring machine (CMM) to obtain the reference dataset. The model was then scanned with two photogrammetric systems-an extraoral device (3Dots®) and an IOS equipped with IPG (Aoralscan Elite IPG®)-as well as four IOSs (TRIOS 6®, CS 3800®, iTero Lumina™, i900®). Ten scans per IOS were performed under standardized conditions. All datasets were processed in CAD software to replace scanbodies (SBs) with their corresponding library geometries and analyzed in reverse-engineering software to measure inter-implant distances. Absolute deviations from CMM data were used to assess trueness. Statistical analysis included descriptive statistics and repeated measures ANOVA with Bonferroni correction (α = 0.05). RESULTS: EPG demonstrated the highest trueness (mean deviation 5 μm), followed by IPG (29 μm) and iTero Lumina™ (34 μm). The i900® (54 μm), TRIOS 6® (84 μm), and CS 3800® (223 μm) exhibited progressively greater deviations. No significant differences were observed among EPG, IPG, and iTero Lumina™, which all outperformed TRIOS 6® (p ≤ 0.020) and CS 3800® (p < .001). Medit i900® and TRIOS 6® were also significantly more accurate than CS 3800® (p < .001). Segment-level analysis revealed higher deviations for longer inter-implant spans. CONCLUSIONS: Within the limits of this study, EPG achieved the highest accuracy and remains the reference method for full-arch implant digitization. IPG and iTero Lumina™ reached comparably high trueness, followed by Medit i900® and TRIOS 6®. CLINICAL RELEVANCE: Next-generation IOSs, particularly iTero Lumina™, may approach the trueness of photogrammetric systems, although photogrammetry-especially EPG-remains the most accurate option for digital full-arch implant acquisition.