Statement of problem The intraoral scanning of the edentulous arch might be challenging
for an inexperienced operator because of the large mucosal area and the use of scan
bodies. Purpose The purpose of this ex vivo study was to compare the trueness of 5
intraoral scanners in replicating implant scan bodies and soft tissues in an edentulous
maxilla and to investigate the effects of operator experience. Material and methods
The maxilla was resected from a fresh cadaver, 5 implants placed, and a reference
scan made. Eight scans were made by experienced operators and 8 by an inexperienced
operator with each scanner (iTero Element 2, Medit i500, Primescan, TRIOS 3, TRIOS
4). The implant platform deviation was measured after complete surface alignment and
after scan body alignment. Deviation data were analyzed with a generalized linear
mixed model (α=.05). Results After complete surface alignment, the mean ±standard
deviation implant platform deviation was higher for the inexperienced operator (421
±25 μm) than for experienced ones (191 ±12 μm, P<.001) for all scanners. After scan
body alignment, no significant differences were found between operators for Element
2, Primescan, and TRIOS 3. The experienced operators produced a lower deviation for
TRIOS 4 (35 ±3.3 μm versus 54 ±3.1 μm, P<.001), but higher deviation for i500 (68
±4.1 μm versus 57 ±3.6 μm, P<.05). The scanner ranking was Element 2 (63 ±4.1 μm),
i500 (57 ±3.6 μm, P=.443), TRIOS 4 (54 ±3.1 μm, P=.591), TRIOS 3 (40 ±3.1 μm, P<.01),
Primescan (27 ±1.6 μm, P<.001) for the inexperienced operator and i500 (68 ±4.1 μm),
Element 2 (58 ±4.0 μm, P=.141), TRIOS 3 (41 ±2.8 μm, P<.001), TRIOS 4 (35 ±3.3 μm,
P=.205), Primescan (28 ±1.8 μm, P=.141) for the experienced operators. Conclusions
Mucosal alignment greatly overestimated the platform deviation. The intraoral scanners
showed different trueness during the complete-arch implant scanning. The operator
experience improved the trueness of the edentulous mucosa but not implant platform
deviation.
