Titanium Scanbody Repeated Use for Complete-Arch Implant Impression: An In Vitro Accuracy Analysis

The aim of the study was to assess the effect of titanium scanbody (Ti ISB) repeated use on the accuracy of complete-arch implant impression in vitro. A mandibular resin model with four conical connection implant analogues was digitized using an extraoral scanner to achieve a reference file. Thirty-eight test files were obtained with an intraoral scanner (IOS) and superimposed to the reference file. Screw-retained sand-blasted Ti ISB were screwed and unscrewed between each test scan. Implant positions (n=152) were analyzed through linear (ΔX, ΔY and ΔZ-axis) and angular deviations (ΔANGLE). Three-dimensional (3D) deviation was calculated as Euclidean distance (ΔEUC) from the linear deviations. Effect of implant position was also calculated. A significative reduction of ΔEUC over time (p=0.001, b=-0.00099) was noticed, with position 4.5 as the least accurate with a significant difference compared to 3.2. Considering ΔANGLE a significant reduction was noticed over time (p=0.041, b=-0.0031), with position 4.5 as the least accurate with a significant difference compared to 3.2 and 4.2. Conclusions: Ti ISBs repeated use didn’t show a significant negative effect on complete-arch IOS implant impression accuracy both in terms of angular and 3D deviation. Implant position showed a significant effect on accuracy with posterior tilted identified as most critical positions.