Evaluation of the Effect of Implants Placed in Preserved Sockets Versus Fresh Sockets on Tissue Preservation and Esthetics: A Meta-analysis and Systematic Review

To compare the success rates, tissue preservation, and esthetics of implants placed in fresh and preserved sockets and to evaluate the factors influencing the outcomes.Medline, Embase, CENTRAL, Wanfang, and China National Knowledge Infrastructure (CNKI) databases were searched electronically, and a manual search was conducted as well. Studies that compared the implant success rate, tissue preservation, and patient-related outcomes such as complications and esthetic outcomes of immediate implant placement (IIP) and alveolar ridge preservation (ARP) were included. A subgroup analysis according to the follow-up period, socket conditions, and regenerative strategies was performed to investigate how these factors influence the prognosis.A total of 12 studies with 588 implants, where 298 are implants after ARP and the remaining 290 are after IIP. The IIP was performed in 58.4% of 250 implants inserted in the sockets with an intact buccal wall, whereas the percentage declined to 41.9% when the buccal wall was defective. The implant success rate was similar between ARP and IIP for an intact buccal wall but different for a defective buccal wall (ARP 98.6% vs IIP 89.6%). Moreover, hard-tissue preservation and the Pink Esthetic Score (PES) of the ARP group were significantly better than those of the IIP group in the molar region (P < .05). Also short-term complications showed no significant differences in the ARP group (P = .06). In the anterior region, there appeared to be no significant difference in hard- and soft-tissue preservation PES and patient-related outcomes between the 2 protocols.An alveolar bone defect might reduce the success rate of IIP. Further studies on the tissue preservation and esthetics of implants placed by IIP and ARP are still needed.