Solid Index versus Impression for transferring the Position of implants in Mandibular total Edentulous Arches: A Clinical study on trueness

To evaluate the trueness of two techniques for transferring the position of implants, with respect to the angles and distances between them, in completely edentulous arches rehabilitated with 3 and 4 implants. All patients were subjected to 2 impressions techniques: solid index (SI) and conventional impression using the open tray (MC) technique. The cast models were digitized by a laboratory scanner, and the generated STL files were imported into engineering software to measure the axes of the coordinates of the implants and the distances between the implants. The Wilcoxon test was used to identify the differences between the SI and MC groups (p<0.05). The Spearman correlation coefficient was applied to identify the correlation between the coordinate axes and the distances between the implants (p<0.05). When comparing the SI and MC groups, a significant difference was observed in the x-axis of implant #1, for the arches with 3 and 4 implants (p<0.05). As for the distances, a significant difference was observed between implants 1-2 in the arches with 4 implants (p<0.05). No correlation was identified between the two dependent variables. The SI, as well as the MC, must be developed to obtain a passive adjustment metal substructure.