Efficacy of autogenous platelet concentrates in immediate implant therapy: A systematic review and meta-analysis of prospective controlled clinical trials.

Purpose: To provide an overview of the outcomes of the use of autogenous platelet concentrates in immediate implant placement.

Materials and methods: Based on an a priori protocol, a systematic search was performed of the National Library of Medicine (MEDLINE via PubMed), Embase and Scopus databases. Randomised and non-randomised controlled clinical trials on immediate implant placement including at least one study arm with use of platelet-rich fibrin or platelet-rich plasma as a gap filler between immediately placed implants and the alveolar bone were included. A random-effects meta-analysis model was built to assess the primary outcomes of marginal bone loss and probing pocket depths between test (platelet concentrates) and control (no graft or other graft materials) groups. A risk of bias assessment was performed and the Grading of Recommendations Assessment, Development and Evaluation approach was used to assess the certainty of evidence.

Results: A total of 20 trials (595 immediate implants placed in 454 individuals) were included in the meta-analytic model. Based on the data from studies with a minimum post-prosthetic loading period of 6 months after immediate implant placement, overall, the application of platelet concentrates was associated with significantly lower marginal bone loss and probing pocket depth compared to the control groups (mean difference -0.36 mm; P < 0.01 and mean difference -0.47 mm; P < 0.01, respectively). No additional benefit of application of platelet concentrates was detected regarding primary stability of immediate implants. Subgroup analysis revealed significantly lower marginal bone loss with xenogeneic bone alone compared to platelet concentrates alone as grafting material in immediate implant placement (mean difference 0.66 mm; P < 0.01). Evidence on soft tissue outcomes and aesthetic parameters was scarce.

Conclusions: A low level of certainty based on the Grading of Recommendations Assessment, Development and Evaluation approach indicates superior outcomes in terms of marginal bone loss and probing pocket depth in immediate implant placement with the use of platelet concentrates versus no graft. Future research should be tailored towards a standardised protocol for preparation of platelet concentrates and inclusion of soft tissue and aesthetic outcomes as well.