Impact Of Four Registration Strategies On Virtual Occlusal Records’ Accuracy

To compare four registration strategies' impact on virtual occlusal records (VOR) accuracy in mandibular free-end edentulism with multiple missing teeth. A typodont model with missing teeth (46, 48, 35-38) was mounted on a semi-adjustable articulator in maximal intercuspal position (MIP). Twelve steel balls (diameter=0.5 mm) were attached at reference positions (16-46, 13-43, 23-33, 25-35, 26-36, and 27-37). Reference datasets were scanned using a laboratory scanner (inEox X5). Four registration strategies were applied using the intraoral scanner (Medit i700): left-side registration (GroupL), right-side registration (GroupR), bilateral registration (GroupB), and anterior-side registration (GroupA). Randomization was performed to minimize bias in strategy sequence. Each strategy was repeated 10 times, generating four VOR datasets. Geomagic Control software measured linear distances and calculated deviations from reference scan. Non-normal data distribution was confirmed, and Kruskal-Wallis tests analyzed accuracy and precision (α = 0.05). Both the scanning strategy and the linear distance positions significantly impacted the VOR accuracy. In mandibular distal extension areas (D2535, D2636, D2737), GroupL and GroupB demonstrated similar performance (P > 0.05), whereas both significantly outperformed GroupR (P < 0.05); conversely, in regions D1343 and D1646, GroupB and GroupR showed superior accuracy over GroupL (P < 0.05) . GroupB achieved the highest trueness (deviations ≤150 μm) across all positions. VOR accuracy decreased significantly in mandibular free-end partial edentulism, risking occlusal vertical dimension underestimation. With Medit i700, bilateral registration achieves the highest VOR accuracy, and warrants clinical application.