Influence of different dental scenarios on the accuracy of computerized optical impressions: an in vitro pilot study

This in vitro study aimed to determine the influence of various dental scenarios on the accuracy of computerized optical impressions (COIM), specifically focusing on trueness and precision.

Eight resin casts representing different dental scenarios, including fully dentate upper (UU) and lower jaws (UL), full-arch preparation (FA), single abutment preparations (SA), anterior (AB) and lateral bridge preparations (LB), partial crown preparations (PA), and veneer preparations (VE), were digitally captured using an extraoral reference scanner and an intraoral scanner. The datasets from both scanners were superimposed to calculate and statistically evaluate three-dimensional mean deviations.

The accuracy of maxillary full-arch scans was lowest in the PA scenario (trueness: 34.18 ± 5.46 μm, precision: 36.0 ± 14.69 μm) and LB scenario (trueness: 33.18 ± 7.86 μm, precision: 47.70 ± 14.09 μm). The best accuracy was observed in the SA (trueness: 21.38 ± 1.87 μm, precision: 22.25 ± 4.31 μm) and FA (trueness: 23.75 ± 1.51 μm, precision: 15.26 ± 3.41 μm) scenarios, significantly better than UU (trueness: 29.67 ± 0.79 μm, precision: 29.51 ± 1.17 μm). Soft tissue included in the scans of UU and UL lowered accuracy.

The accuracy of COIM varies significantly with different dental scenarios. Scenarios with extensive edentulous areas and complex preparation designs exhibit lower accuracy.

Accurate dental impressions are vital for the proper fit of prosthetic restorations. This study highlights that scenarios with less edentulous areas and simpler preparation designs yield better accuracy. Clinicians should be mindful that large edentulous areas and complex preparations can pose challenges for intraoral scanners, requiring careful scanning strategies to mitigate potential inaccuracies.