Clinical parameters of implants placed bone level with cover screw or healing abutment techniques. 6 months post-surgery report from a randomized controlled clinical trial

Objective: This randomized clinical trial evaluated marginal bone level (MBL) changes and peri-implant soft tissue health in single implants placed at crestal bone level, comparing healing abutments exposed at gingival level versus cover screws submerged with a flap. Methods: Sixty-six PrimeTaper implants (Dentsply, Mannheim, Germany) were placed in 45 healthy adult patients and randomized to either the healing abutment group (n = 34) or the cover screw group (n = 32). A fully digital workflow was used for provisional and definitive zirconia crowns delivered at 3-4 months. Clinical and radiographic follow-ups were performed at baseline, 3 and 6 months. Outcomes included Bleeding upon Scanbody positioning (BuSP), bleeding upon Prosthetic Abutment application (BuPA) and Mombelli modified plaque score, MBL, and prosthetic complications. Results: Baseline characteristics were balanced between groups. Implant survival was 100%, with one mucositis case in the healing abutment group. Soft tissue assessment revealed reduced BuSP in the healing abutment group, where approx. 75% of implants showed no BuPA at follow-up (p < 0.001). Mombelli modified plaque score improved over time and did not differ significantly between groups. Conclusion: Both techniques yielded stable peri-implant tissues and comparable MBL changes at 6 months. Healing abutment application reduced bleeding during prosthetic clinical procedures and avoided flap re-entry, offering a simpler, less invasive, and equally effective alternative to cover screw protocols.