Simultaneous sinus-lift and implantation using microthreaded implants and leukocyte- and platelet-rich fibrin as sole grafting material: a six-year experience.

PURPOSE To assess the relevance of simultaneous sinus-lift and implantation with leukocyte- and platelet-rich fibrin (L-PRF, Choukroun's technique) as sole subsinus filling material. MATERIALS Twenty-three lateral sinus elevations (SA4 sinus) were performed on 20 patients with simultaneous implant placement. Seven patients were treated with 19 Astra implants (AstraTech, Mölndal, Sweden) and 13 patients with 33 Intra-Lock implants (Intra-Lock Ossean, Boca Raton, FL). L-PRF membranes were used to cover the Schneiderian membrane, the implant tips served as "tent pegs" for the L-PRF-patched sinus membranes, and the subsinus cavity was finally filled with L-PRF clots. Clinical and radiographic follow-up was performed just after implant placement, after 6 months, 1 year and each following year. RESULTS Six months after surgery, all implants were clinically stable during abutment tightening. The maximum follow-up was 6 years, and all patients were followed up for a minimum of 2 years. No implant was lost during this 6-year experience, and the vertical bone gain was always substantial, between 8.5 and 12 mm bone gain (10.4 ± 1.2). The final level of the new sinus floor was always in continuation with the implant apical end, and the periimplant crestal bone height was stable. CONCLUSION The use of L-PRF as sole filling material during simultaneous sinus-lift and implantation seems to be a reliable surgical option promoting natural bone regeneration.