In vitro comparison between complete arch abutment-level implant impressions with photogrammetry, grammetry, and intraoral scanning

Statement of problem: Photogrammetry (PG) has emerged as a promising recording technique for fabricating implant-supported prostheses. However, the existing evidence on the accuracy of dental PG devices is still limited. Purpose: The purpose of this in vitro study was to evaluate the trueness and precision of a newly introduced advanced PG device (MicronMapper; SIN 360) by comparing it with grammetry and intraoral scanning. Material and methods: Four implants (BioHorizons) were placed in an edentulous mandibular model. Multi-unit abutments (BioHorizons) were positioned and tightened to 30 Ncm. A digital reference cast (Control group) was obtained by scanning the model with a laboratory scanner (inEosX5; Dentsply Sirona). Three test groups were evaluated: PS (Primescan), PS-OS (Primescan and OptiSplint), and PG (MicronMapper; SIN 360). Test files were superimposed with the reference file (trueness) and pairwise within groups (precision) using a 3D evaluation software program (Geomagic Control X). Root mean square (RMS) values were calculated. Analysis of variance (ANOVA) was used to analyze differences in RMS values among groups (α=.05), followed by the Tukey post hoc test. Results: For trueness, group PG showed the lowest mean ±standard deviation RMS values (20.5 ±0.6 µm), followed by PS-OS (30.9 ±16.8 µm) and PS (56 ±0.7 µm). A statistically significant difference was found between groups PG and PS (P<.001), as well as PS-OS and PS (P=.004). For precision, the lowest RMS values were detected in group PG (6 ±1.2 µm), followed by PS (9.5 ±3.3 µm) and PS-OS (23.3 ±22.3 µm). No statistically significant differences were detected among the test groups in terms of precision (P=.192). Conclusions: Photogrammetry obtained the best accuracy. Grammetry improves the trueness; however, it appears to have no positive impact on the precision of complete arch implant recordings.