Comparative Evaluation of Marginal Bone Loss and Soft Tissue Thickness in Posterior Implants Placed using Single Stage and Two Stage Protocols: A Clinical Study

Abstract

Background: Dental implants are a predictable treatment modality for the rehabilitation of partially edentulous patients. Long-term success is influenced by peri-implant hard and soft tissue stability, particularly marginal bone levels and soft tissue thickness. The choice of surgical protocol—single-stage (non-submerged) or two-stage (submerged)—may affect peri-implant tissue response, although existing literature presents conflicting evidence. Aim: To evaluate and compare marginal bone loss and peri-implant soft tissue thickness between single-stage and two-stage implant placement protocols in the mandibular posterior region. Materials and Methods: This prospective, randomized controlled clinical and radiographic study included 30 partially edentulous patients requiring implant-supported rehabilitation in the mandibular posterior region. Participants were randomly divided into two groups: ● Group A: Single-stage implant placement ● Group B: Two-stage implant placement Marginal bone levels were assessed using standardized intraoral periapical radiographs at baseline (T0), 3 months (T1), and 6 months (T2). Peri-implant soft tissue thickness was measured using the transgingival probing method at corresponding time intervals. Intragroup and intergroup comparisons were performed using appropriate statistical analysis. Results: Both groups demonstrated acceptable marginal bone remodeling and soft tissue healing over the study period. However, the single-stage implant placement protocol showed comparatively lesser marginal bone loss and slightly greater peri-implant soft tissue thickness than the two-stage protocol. The differences were found to be clinically favorable toward the single-stage approach. Conclusion: Both single-stage and two-stage implant placement protocols are clinically reliable for implant rehabilitation. However, the single-stage protocol may offer advantages in terms of reduced marginal bone loss, improved peri-implant soft tissue thickness, decreased treatment time, and elimination of a second surgical procedure. Further long-term studies are recommended to substantiate these findings.