The goal of this clinical trial is to compare the accuracy of two denture impression techniques, digital intraoral scanning and conventional border-molded impressions, in adults who have lost all their teeth (fully edentulous patients). The main questions it aims to answer are: Is a digital intraoral scan as accurate as a conventional impression for capturing the shape of the mouth, including movable gum areas? Are repeated digital scans consistent (precise) when taken multiple times on the same patient? Researchers will compare digital impressions taken with an intraoral scanner to conventional impressions made with custom trays and border molding to see if digital scans can match the accuracy of the traditional "gold standard" method. Participants will: Attend Dubai Dental Hospital for two study visits. Have their mouth scanned three times using a digital intraoral scanner. Have a conventional impression taken using a custom tray and high-accuracy material after border molding. Provide informed consent and allow their impression data to be analyzed for accuracy.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
10
Participants will first receive digital intraoral scanning of their fully edentulous upper and/or lower jaw using the TRIOS 5 intraoral scanner (3Shape). The scanning process follows a structured sequence to capture the entire arch, including the palate and ridge slopes. Each arch will be scanned three times during the same visit to assess precision (consistency of repeated scans). Then the same participants will also undergo a conventional impression procedure using a custom tray and border molding technique.
Dubai Dental Hospital
Dubai, United Arab Emirates
RECRUITINGTrueness of Digital Impressions: Mean root mean square Deviation (mm) between intraoral scanner (IOS) digital impressions and conventional impression scans-per arch
Trueness will be checked by looking at the Root Mean Square (RMS) deviation (mm) after superimposing the IOS Standard Tessellation Language (STL) over the conventional impression scan STL (reference) using Geomagic Control X. The primary metric is the participant-level mean RMS over the full arch surface (edentulous maxilla and mandible analyzed separately). Lower RMS indicates greater trueness (higher accuracy). Region-specific RMS (static vs. dynamic tissues) will be recorded as prespecified analyses (see secondary outcomes). Alignment: Initial + best-fit alignment; conventional scan = reference file. Reporting (participant level): Mean RMS (mm) per arch. Reporting (study level): Mean \[Standard Deviation (SD)\], RMS per arch; 95% CI; distribution plots as applicable. Unit of Measure: millimeters (mm), RMS deviation Regions analyzed: Static (palatal rugae, ridge slopes, crest) and dynamic (labial, buccal, lingual sulci, hamular notch, posterior palatal seal).
Time frame: 1 week
Precision of Digital Impressions: Within-Subject Mean Pairwise RMS Deviation (mm) Across Three IOS Scans (Precision)-per Arch
Precision will be quantified by pairwise deviation analysis between three repeated IOS scans per arch taken on the same day. STL files will be aligned (Initial + Best-Fit ICP) in Geomagic Control X. For each arch, the following pairs will be analyzed: (Scan1-Scan2), (Scan1-Scan3), and (Scan2-Scan3). Each pair will be aligned in both directions (each file alternately as reference), and all RMS values will be averaged to yield the participant-level mean pairwise RMS (mm) for that arch. Lower RMS indicates greater precision (repeatability). Reporting (participant level): Mean of all pairwise RMS values per arch. Reporting (study level): Mean (SD) RMS per arch; 95% CI; distribution plots as applicable. Unit of Measure: millimeters (mm), RMS deviation
Time frame: 1 week
The difference (mm) in mean RMS trueness between the maxillary and mandibular arches is measured.
Compute mean RMS trueness (mm) per arch (as defined in Primary Outcome 1). The between-arch difference will be calculated as maxilla minus mandible (mm). Positive values indicate higher RMS (worse trueness) in the maxilla. Reporting (study level): Mean (SD) difference; 95% CI; paired analysis. Unit of Measure: millimeters (mm), RMS deviation
Time frame: 1 week
Difference (mm) in mean RMS trueness between static (attached) and dynamic (mobile) regions.
Within each arch, participant-level trueness RMS (mm) will be computed separately for prespecified static regions (palatal rugae; buccal and palatal/lingual slopes; ridge crest) and dynamic regions (labial, buccal, and lingual sulci; hamular notch; posterior palatal seal). The regional difference will be calculated as Dynamic minus Static (mm). Positive values indicate higher RMS (worse trueness) in mobile tissues. Reporting (study level): Mean (SD) difference; 95% CI; by arch as applicable. Unit of Measure: millimeters (mm), RMS deviation
Time frame: 1 week
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