Influence of Pre-Prosthetic Periodontal Surgery on the Stability of Peri-Implant Tissues and Prosthetic Success: A Randomized Controlled Trial

A BSTRACT Background: Long-term success of dental implants relies on stable peri-implant tissues and predictable prosthetics. Pre-prosthetic periodontal surgery (PPPS) aims to optimize implant sites, but robust randomized controlled trial (RCT) evidence on its impact on tissue stability and prosthetic outcomes was limited. This RCT is the first to evaluate the long-term impacts of PPPS concerning the stability of peri-implant tissues and success with the prosthetic components over two centers. The benefits of PPPS were conclusively established thanks to our large-scale sample and standardized multi-site methods, which enhanced external validity and bolstered clinical recommendations. Materials and Methods: This prospective, dual-center, parallel-group RCT included 80 patients. Patients required implants in sites with insufficient keratinized tissue (<2 mm) or inadequate bone. Participants were randomized ( n = 40/group): Test (PPPS + implant) or Control (implant only). Standardized protocols were used. Primary outcomes were peri-implant soft tissue (keratinized tissue width [KTW], probing depth [PD], bleeding on probing [BOP], mucosal recession [MR]) and radiographic marginal bone loss (MBL), assessed at 6, 12, 24 months post-loading. Secondary outcomes included prosthetic complications, patient-reported outcome measures (PROMs), and implant survival. Statistical significance was P < 0.05. Results: The Test Group showed significantly greater KTW (3.4 ± 0.6 mm vs. 1.1 ± 0.3 mm at 24 months, P < 0.001) and less MBL (0.35 ± 0.15 mm vs. 0.78 ± 0.25 mm at 24 months, P < 0.001). BOP was lower (12.5% vs. 30%, P = 0.03), and peri-implant mucositis reduced (5.3% vs. 18.9%, P = 0.04) in the Test Group. Patient satisfaction was significantly higher (OHIP-14 lower, VAS higher). Implant survival was comparable (97.4% vs. 94.6%, P = 0.61). Conclusion: PPPS enhanced peri-implant soft tissue, intraoral tissue stabilization, marginal bone resorption, prosthetic performance, and patient satisfaction metrics. These findings advocate for PPPS in strategies where tissue volume is insufficient to optimize long-term outcomes with implants.