Comparing Single-Tooth Implant Placement With and Without Allogeneic Soft Tissue Augmentation: A Randomized Clinical Trial

Purpose: To explore the effect of adding an allogeneic soft tissue graft at the time of single implant placement using a fully digital workflow for implant placement and restoration without making either analog or digital impressions. Materials and Methods: A prospective randomized clinical study was performed enrolling 39 participants requiring single-tooth implants. The patients were randomized into one of two groups: (1) the graft group, which received an allogeneic dermal graft at the time of implant placement (n = 19), or (2) the nongraft group (n = 20). A fully digital surgical and restorative protocol was implemented for both groups. Intraoral scans were taken before implant placement (T0), at the time of final crown delivery (T1), and 1 year after placement (T2). Intraoral scans were aligned using Geomagic Control X 2020 software, and linear and volumetric changes in buccal tissues were measured at T0, T1, and T2. Implant survival, probing depths (PDs), and complications were recorded. Participants were asked to complete an Oral Health Impact Profile (OHIP)- 14 survey at T0 and T2. Marginal bone levels were measured at T0 and T2 on periapical radiographs. Results: Overall, 39 participants completed surgery and restoration in the incisor, canine, premolar, and molar sites. Two early failures were recorded in central incisor positions (95% survival). Crown delivery without complication from the digital workflow (impressionless) was achieved for 36 out of 39 cases (92%), and implant depth control was the main challenge. At 1 year, 37 participants attended the follow-up appointment. Both groups showed gain in buccal tissue thickness without significant differences between the two groups for both linear and volumetric measurements (P > .05). Soft tissue grafting was associated with minimal added morbidity. The interproximal marginal bone changes were recorded as follows: –0.16 mm mesial and –0.12 mm distal for the graft group and –0.01 mm mesial and –0.11 mm distal for the nongraft group (P = .07 for mesial and .83 for distal). The OHIP score was significantly reduced at T2 compared to T0 (P = .003) for the entire cohort. Conclusions: Augmentation of the alveolar mucosa on the buccal aspect of single-tooth implants is associated with clinically favorable outcomes. A fully digital workflow has been validated to permit crown delivery on CAD/CAM abutments without implant impressions.