The Acceptability of Digital Impression Compared to Conventional Technique in Children - A Randomized Controlled Clinical Trial

This randomized crossover clinical trial aims to evaluate and compare the acceptability, comfort, time efficiency, and anxiety levels associated with digital intraoral impressions versus conventional alginate impressions in children aged 6 to 11 years. Dental impressions are essential in pediatric treatment planning, yet conventional alginate techniques are often poorly tolerated by children due to discomfort, taste, gagging, and procedural anxiety. Advances in digital dentistry, particularly intraoral scanners (IOS), provide a less invasive alternative with potential to enhance patient cooperation and improve the overall experience. Despite their growing use in adult patients, evidence regarding children's acceptance of intraoral scanning remains limited, particularly in the Middle East.

This study will be conducted at the Pediatric Dentistry Department of Beirut Arab University over a four-month period and will involve 40 pediatric patients who require dental impressions for fixed or removable appliances. A 1:1 randomization process will assign participants to one of two sequences: Group 1 will receive a digital impression first, followed by a conventional impression after a 14-21 day washout period; Group 2 will receive the procedures in reverse order. All procedures will be performed by a single calibrated operator.

Digital impressions will be made using the Medit i700 intraoral scanner, which allows 3D image acquisition without physical materials or trays. The scanning process includes drying the teeth and capturing occlusal, lingual, and buccal surfaces. Conventional impressions will be obtained using Hydrogum 5 alginate, involving tray selection, alginate mixing, and taking maxillary and mandibular impressions, followed by disinfection.

To assess acceptability and experience, several outcome measures will be recorded. Patient comfort and specific sensory responses will be measured using a Visual Analog Scale (VAS), where children will rate domains such as general feeling, breathing difficulty, taste or smell discomfort, thermal discomfort (heat/cold), gag reflex, and pain. Operator-assessed anxiety levels will be scored using the Venham's Clinical Anxiety Scale (VCAS), ranging from 0 (no anxiety) to 5 (severe anxiety). Total procedure time will be recorded using a digital stopwatch, beginning at tray or scanner insertion and ending at procedure completion. After both procedures, a structured comparative questionnaire will be administered to children, their parents, and the operator to assess perceived comfort, ease, duration, and preference.

Additionally, the operator's subjective perception of difficulty, applicability, and preference for each method will be documented. Intra-examiner reliability for digital scanning will be evaluated using repeated scans of 10 cases at a 48-hour interval, with agreement assessed via Cohen's Kappa statistic.