Effect of assistive devices on the precision of digital implant impressions for fully edentulous maxilla: An in vivo study.

Purpose: This study examined the effect of assistive device use on the precision of digital impressions for multiple implants placed in a fully edentulous maxilla in vivo.

Methods: A total of eight participants with fully edentulous maxillae and four implants at position #15, #12, #22, and #25 were included in the study. The assistive device was made using CAD/CAM technology. Digital impressions were obtained using an intraoral scanner with (AD+) and without (AD-) the assistive device that attached to the scan bodies. Each participant underwent five digital and conventional impressions (verification casts (VC)). Dimensional deviations for each impression method were measured using the least-squares best-fit method to assess precision. Statistical analysis was performed using one-way analysis of variance (ANOVA) with Tukey's post-hoc adjustments for multiple comparisons.

Results: The dimensional deviations were as follows: AD- (37.56 ± 7.43 µm), AD+ (16.23 ± 2.56 µm), and VC (26.48 ± 5.13 µm). One-way ANOVA revealed significant differences between the groups (F = 31.04, P < 0.0001), which remained after Tukey adjustment (P < 0.01). The AD+ group exhibited the highest precision, while the AD- group had the lowest.

Conclusions: For implants placed in a fully edentulous maxilla in vivo, digital impressions with assistive devices demonstrated superior precision compared with those obtained without assistive devices or conventional impressions obtained with an implant indexing device.