Effect of abutment shape on soft tissue healing: a randomized clinical pilot study with a digital superposition methodology.

This article reports on a randomized clinical pilot study investigating the effect of healing abutment shape—concave versus straight—on peri-implant soft tissue dimensions after healing. Using a novel digital superposition methodology that merges cone beam computed tomography (CBCT), intraoral scans (IOS), and standard tessellation language (STL) files of abutments, the study measured changes in gingival height, width, and emergence angles around 27 implants placed in the posterior jaws of 13 patients. Results showed no significant difference in gingival height between concave and straight abutments; however, gingival thickness at concave abutments depended on whether the marginal gingiva extended beyond the concavity or remained within it, with greater thickness observed when the gingiva reached beyond the concavity. Emergence angles similarly varied with gingival position relative to the concavity. The study concludes that while abutment shape does not affect gingival height, careful selection of concave abutment height is necessary to ensure beneficial soft tissue thickening, highlighting the potential of this digital methodology for detailed peri-implant soft tissue assessment.