In vivo prospective clinical study will be designed, 12 participants will be included. After intraoral scanning, a conventional impression is made for each patient. The groups will be compared for accuracy.

• Recruit 12 eligible edentulous patients

• Scanning Process: Perform five intraoral scans (IOS) of the maxillary flabby ridges for each patient.

  . WTI: perform five WTI for each patient

• STL Export: Export scans and corresponding cast scans obtained via the Window Technique Impression (WTI) as STL files using the intraoral scanner software.

• 3D Distance Measurement: Import IOS and cast STL files into Geomagic Wrap 2017 for a two-phase best-fit alignment, using the Cast scan as the reference for evaluating trueness and precision.

• Comparison of Scans:

  • Compare the IOS scan and corresponding cast scan obtained via the Window Technique Impression (WTI) to calculate trueness -compare WTI and corresponding cast scan obtained via the Window Technique Impression (WTI) to calculate trueness-
  • Compare each of the five IOS impressions by using each scan as a reference against the others to calculate precision.
  • Compare each of the five WTI impressions by using each scan as a reference against the others to calculate precision. • Deviation Analysis: Generate a color difference map of each superimposition for visual analysis of deviation patterns.

Inclusion Criteria:Inclusion criteria for participant selection will be as follows: 1. completely edentulous patients with maxillary flabby ridge; 2. Absence of infectious diseases; 3. Systemic good health (ASA-1/ASA-2). .; 4. Age between 50 and 75 years; 5. Willingness to cooperate throughout the data collection process.

Exclusion Criteria:Exclusion criteria included: 1. Presence of any remaining teeth; 2. Inability to comprehend the study's objectives and procedures; 3. ridge defect or lesion; 4. Postoperative scarring on the ridge; 5. Limitations in mouth opening.