Introduction: The procedural errors associated with conventional interocclusal records (CIRs) have been mitigated by the use of intraoral scanners (IOSs) for virtual interocclusal records (VIRs). However, in cases requiring multiunit fixed restorations the precision of (VIRs) is questionable.
Objectives: This in vitro study aimed to evaluate the precision of IOS for VIRs in maximal intercuspal position (MIP) for multiunit fixed restorations.
Material and methods: Five pairs of 3-dimensionally (3D) printed master models represented five different clinical situations as follows: Full dentate (FD), short span posterior (SSP), long span posterior (LSP), short span anterior (SSA), and long span anterior (LSA). Fourteen pairs of interarch reference points were added to each set of master models to measure linear interarch distance. For MIP registration with VIRs, each pair of master models were scanned 10 times with Medit i700 IOS, and the virtual models were articulated with 10 VIRs. Digital linear interarch measurements on all virtually-articulated models were compared with reference measurements obtained with a digital caliper on master models.
Results: All study groups had a mean value for interarch deviations less than 100 µm as follows: group FD: 9.21±6.04 µm, group SSP: 24.71±13.44 µm, group SSA: 12.79±5.35 µm, group LSP: 22.43±11.02 µm and group LSA: 29.43±33.67 µm. Groups SSP, LSP and LSA had significantly higher deviations in comparison to FD group (P0.05), while SSA group did not show a significant difference from FD group (p=0.054).
Conclusion: The span length and location of prepared areas significantly impacted the accuracy of VIRs.