Comparison of three conventional impression techniques for flabby tissues with intraoral digital scans

Accurate impression making for flabby anterior maxillary ridges in edentulous patients remains challenging with conventional techniques, necessitating comparison of their trueness against intraoral digital scanning. Hence, the present study included twenty patients with maxillary edentulism and Siebert Class I or II anterior flabby ridges were included in this crossover clinical study. Four impression methods were performed for each participant: 1) Single-Step Mucocompressive Technique (SMT) with polyvinyl siloxane (PVS) in a stock tray; 2) Window Tray Technique (WTT) using a custom tray with zinc oxide eugenol and light-body PVS; 3) Modified Mucostatic Technique (MMT) with a spaced custom tray and light-body PVS; and 4) Intraoral Digital Scan (IDS) using a structured light scanner. The trueness of each technique was evaluated by superimposing the digital models onto the RSM and calculating the root mean square error (RMSE) in micrometers (µ). The window tray technique produced the most accurate impressions of flabby ridges.