Dimensional Variations in the Soft Tissue Profile After Removal of Implant-Supported Fixed Interim Restorations: A Pilot Clinical Study

Purpose: To measure dimensional changes of the periimplant soft tissue profile after removal of a single implant fixed interim restorations using digital impression procedures. Materials and Methods: Ten participants presenting with single implant- supported fixed interim restorations (ISFIRs) on the maxillary esthetic zone. A 2-step silicone impression was made of the maxillary arch with the ISFIRs. The experimental procedure was obtained by making digital impressions of the gingival contours immediately after ISFIR removal. The control procedure was formed by fabricating definitive casts from the conventional impression using the ISFIRs as a customized impression transfer and making digital impressions of these definitive casts. Both images of paired groups were digitally overlapped on the computer, and their profiles were measured at the coronal, midlevel gingiva in the buccolingual and mesiodistal width. Results: Statistically significant differences between the ISFIR emergence profile width and the unsupported soft tissue profile width were observed at the midlevel gingiva in the buccolingual dimension (1.35 mm) and at the coronal (0.51 mm) and midlevel gingiva (1.29 mm) in the mesiodistal dimension. Conclusions: A digital impression, as used in this pilot study, does not capture accurately the desired soft tissue dimensions immediately after removal of the ISFIR.