The Relevance of Choukroun's Platelet-Rich Fibrin and Metronidazole During Complex Maxillary Rehabilitations Using Bone Allograft. Part II: Implant Surgery, Prosthodontics, and Survival

Abstract

Extensive bone grafting remains a delicate procedure, due to the slow and difficult integration of the grafted material into the physiological architecture. The recent use of platelet concentrates aims to improve this process of integration by accelerating bone and mucosal healing. Choukroun's platelet-rich fibrin (PRF) is a healing biomaterial that concentrates in a single autologous fibrin membrane, most platelets, leukocytes, and cytokines from a 10-mL blood harvest, without artificial biochemical modification (no anticoagulant, no bovine thrombin). In this second part, we describe the implant and prosthetic phases of a complex maxillary rehabilitation, after preimplant bone grafting using allograft, Choukroun's PRF membranes, and metronidazole. Twenty patients were treated using this new technique and followed up during 2.1 years (1-5 years). Finally, 184 dental implants were placed, including 54 classical screw implants (3I, Palm Beach Gardens, FL) and 130 implants with microthreaded collar (46 from AstraTech, Mölndal, Sweden; 84 from Intra-Lock, Boca Raton, FL). No implant or graft was lost in this case series, confirming the validity of this reconstructive protocol. However, the number of implants used per maxillary rehabilitation was always higher with simple screw implants than with microthreaded implants, the latter presenting a stronger initial implant stability. Finally, during complex implant rehabilitations, PRF membranes are particularly helpful for periosteum healing and maturation. The thick peri-implant gingiva is related to several healing phases on a PRF membrane layer and could explain the low marginal bone loss observed in this series. Microthreaded collar and platform-switching concept even improved this result. Multiple healing on PRF membranes seems a new opportunity to improve the final esthetic result.

Does platform switching really prevent crestal bone loss around implants?

“…The concept of PLS has been considered in numerous articles, including case reports [8][9][10][26][27][28][29][30][31]. These case reports and some clinical findings suggest preservation of the peri-implant crestal bone and superior soft tissue conditions around PLS implants.…”

Comparative Evaluation of Coronally Advanced Flap with Platelet-rich Fibrin vs Amniotic Membrane for the Treatment of Gingival Recession

“…6 Unlike other platelet concentrates, PRF requires neither anticoagulants nor bovine thrombin (nor any other gelling agent). It results from a natural and progressive polymerization occurring during centrifugation 7 which accumulate platelets, leukocytes, and their released cytokines in a three-dimensional (3D) fibrin network.…”

Management of a Traumatized Open Apex Tooth with a Combination of Mineral Trioxide Aggregate Apical Plug and Platelet-rich Fibrin Apical Matrix

“…19 First, the fibrin clot plays an important mechanical role, with the PRF membrane maintaining and protecting the grafted biomaterials and PRF fragments serving as biological connectors between bone particles. Second, the integration of this fibrin network into the regenerative site facilitates cellular migration, particularly for endothelial cells necessary for the neo-angiogenesis, 20 vascularization, and survival of the graft. Third, the platelet cytokines (platelet-derived growth factor, transforming growth factor, insulin-like growth factor-1) are gradually released as the fibrin matrix is resorbed, thus creating a perpetual process of healing.…”