Full-Arch Digital Implant Impression Trueness: An in Vivo Study

Objectives

To evaluate the trueness of maxillary and mandibular full-arch implant digital impressions with and without additional reference objects.

Material and Methods

Seventeen maxillary and 6 mandibular arches with four implants were randomly divided into a group with additional reference objects (wRO group, n = 12) and without them (woRO group, n = 11) and scanned with an intraoral scanner (IOS). For each jaw, the control model (CM) data was obtained to evaluate the deviations in the scan body positions in the wRO and woRO groups. CM and IOS data sets were imported into metrology software for distance and angle measurements between scan body pairs 1–2, 1–3, and 1–4. Unsigned values of distance and angle data differences between CM and IOS groups were used for further analysis.

Results

The highest statistically significant (p < 0.05) differences between distance and angulation measurements of the maxilla and mandible were observed in the 1–4 scan body pair group (136 ± 95 μm, 0.95° ± 0.79°; 362 ± 233 μm, 2.22° ± 2.11°, respectively). Distance deviations of the mandible were higher in all scan body pair groups. The woRO group had higher distance and angulation unsigned trueness values than in the wRO group, especially in the 1–4 scan body pair (224 ± 183 μm, 1.77° ± 1.76°;169 ± 162 μm, and 0.83° ± 0.57°, respectively).

Conclusions

IOS for the full-arch cases had statistically and clinically significant distance and angle deviations. Higher deviations were observed in the single mandibular scan body pair. The tendency of diminished distance and angular deviations with the utilization of the additional reference objects was observed, though these differences were not statistically significant.