Comparison of conventional and digital impression approaches for edentulous maxilla: clinical study.

Background: The expectations for the clinical and laboratory phases of tissue-supported complete dentures (TSCDs) are changing. Currently, there is a trend towards fast, comfortable, reliable, and low-cost methods. In TSCD impressions, simplified impression and digital impression methods involving the use of an intraoral scanner (IOS) are becoming preferable. Given this situation, this study aims to compare different conventional and digital impression methods used in TSCDs.

Methods: Patients with maxillary complete edentulism and healthy oral mucosa were included in this study. In the digital group, two different impressions were made using an IOS (Trios4) without (D1) and with (D2) artificial intelligence scanning (AI-Scan). In addition, a modified impression (D3) was made using the IOS in two steps, including the occlusal rim. In the conventional group, a two-step impression (C1) using an individual tray with zinc oxide eugenol and a one-step simplified impression (C2) using a stock tray with irreversible hydrocolloid were made. The comparison groups were determined to be C1-C2, C1-D1, D1-D2, and D1-D3. The best-fit algorithm was used to superimpose the impressions to be compared. The right and left vestibular areas, postdam area, palatal area, right and left matching area, entire surface, and borders were evaluated separately.

Results: Fifteen patients were included in this study. In the C1-C2 group, the mean deviation at the borders was statistically significant (p = 0.01). No regions in the C1-D1 and D1-D3 groups exhibited significant differences in the mean amount of deviation (p > 0,05). In the D1-D2 group, the mean deviation in the palatal area was significant (p = 0,03).

Conclusion: In maxillary edentulism, digital impressions have shown comparable results to conventional impressions, suggesting promising implications for clinical applications.

Trial registration: The clinical trial has been registered (ClinicalTrials.gov ID NCT06400277, registration date 06/05/2024, 'retrospectively registered').