Efficacy of different surgical techniques for peri-implant tissue preservation in immediate implant placement: a systematic review and meta-analysis

Introduction Preserving peri-implant tissues after immediate implant placement (IIP), especially in aesthetic zones, is a topic of interest. Objectives This systematic review investigated the effects of currently available surgical procedures for preserving peri-implant tissue or ensuring dimensional stability following immediate implant placement. Materials and methods The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement's guidelines were followed, and articles were sought on the PubMed and Cochrane databases with no date restrictions. Only randomised clinical trials that evaluated changes in soft and hard tissues around immediately placed implants were included. Statistical analyses were performed, and the studies ' quality was assessed using the Cochrane Collaboration tool. The agreement between reviewers was assessed based on Cohen's kappa statistics. Results Of the 14 studies that met the inclusion criteria, 11 were analysed in the meta-analysis (kappa = 0.814; almost perfect agreement). The use of connective tissue grafts resulted in a significantly greater improvement of the facial gingival level (MD = -0.51; 95% CI: -0.76 to -0.31; p = < .001), and the placement of bone grafts significantly reduced the horizontal resorption of the buccal bone (MD = -0.59; 95% CI: -0.78 to -0.39; p < .001). Conclusion Connective tissue grafts and bone grafts positively influence tissue preservation around immediately placed implants. Neither the flapless technique nor palatal implant positioning resulted in significant improvements to any of the investigated parameters. Additional longitudinal studies are required.