Immediate implant placement into posterior sockets with or without buccal bone dehiscence defects: A retrospective cohort study

Objectives: To evaluate bone reconstruction and soft tissue reactions at immediate implants placed into intact sockets and those with buccal bone dehiscence defects. Methods: Fifty-nine internal connection implants from four different manufacturers were immediately placed in intact sockets(non-dehiscence group, n = 40), and in alveoli with buccal bone dehiscence defects: 1) Group 1(n = N10), the defect depth measured 3-5 mm from the gingival margin. 2) Group 2(n = 9), the depth ranged from 5 mm to 7 mm. The surrounding bony voids were grafted with deproteinized bovine bone mineral (DBBM) particles. Cone beam computed tomography(CBCT) was performed immediately after surgery (T1), and at 6 months later(T2). Radiographs were taken at prosthesis placement and one year postloading(T3). Soft tissue parameters were measured at baseline (TO), prosthesis placement and T3. Results: No implants were lost during the observation period. For the dehiscence groups, the buccal bone plates were radiographically reconstructed to comparable horizontal and vertical bone volumes compared with the non-dehiscence group. Marginal bone loss occurred between the time of final restoration and 1-year postloading was not statistically different(P = 0.732) between groups. Soft tissue parameters did not reveal inferior results for the dehiscence groups. Conclusions: Within the limitations of this study, flapless implant placement into compromised sockets in combination with DBBM grafting may be a viable technique to reconstitute the defected buccal bone plates due to space maintenance and primary socket closure provided by healing abutments and bone grafts. Clinical significance: Immediate implants and DBBM grafting without using membranes may be indicated for sockets with buccal bone defects.