Accuracy of Intraoral Scanning at Varying Implant Depths and Resulting Scan Body Exposures in Anterior Immediate...

This study evaluated the accuracy of intraoral scanning at varying implant depths and resulting scan body exposures in maxillary anterior immediate implant placement.

Three identical custom-made epoxy resin models were fabricated with extraction sockets present in the positions of teeth #6 and #11. Dental implants were placed at six different depths apical to the facial mucosal zenith (2.0, 3.0, 4.0, 5.0, 6.0, 7.0 mm), corresponding to of six different amounts of scan body exposure incisal to the facial mucosal zenith (8.9, 7.9, 6.9, 5.9, 4.9, 3.9 mm). Two hundred and forty intraoral scans (TRIOS 4, 3 Shape) were obtained by two independent examiners (twenty times per sites). The generated stereolithography files (STL files) were superimposed onto reference desktop scan files (D710, 3Shape) and analyzed using Geomagic Control X software with best-fit function. Accuracy (trueness and precision) of implant position were evaluated and reported as linear and angular deviations. The null hypothesis is that scanning accuracy would not differ significantly between the tested implant depths.

Accuracy was relatively consistent with high trueness (˂30 µm) across the tested implant depths and resulting scan body exposures. Slightly higher variability was present in angular deviation at intermediate depths (notably 3.0 mm, with 0.053 ±0.026 degrees deviation). Therefore, the null hypothesis was accepted.

Within the limitation of this in vitro study, in maxillary anterior immediate implant placement, the scanning showed consistent high accuracy (<30 μm) across the tested depth levels. Also, the angular deviations were consistently low (<0.1 degrees). A digital workflow using an intraoral scanner and scan body should be clinically applicable for immediate implant placement and provisionalization scenarios within a range of scan body exposures incisal to the mucosa.