Immediate loading – All-on-2 versus All-on-4

gennaio 1, 2011 in Articoli, Carico Immediato

Immediate loading of 2 (all-on-2) versus 4 (all-on-4) implants placed with a flapless technique supporting mandibular cross-arch fixed prostheses: preliminary results from a pilot randomised controlled trial 

Gioacchino Cannizzaro, Pietro Felice, Elisa Soardi, Vittorio Ferri, Michele Leone, Marco Esposito

  • Purpose: To evaluate the clinical outcome of 2 implants versus 4 implants placed flapless in fully edentulous mandibles and immediately restored with metal-resin screw-retained cross-arch pros- theses.
    Materials and methods: Sixty patients from two different centres were randomised: 30 to the all- on-2 group and 30 to the all-on-4 group. To be immediately loaded, implants had to be inserted with a minimum torque of 40 Ncm. Outcome measures were prosthesis and implant failures, and biological and biomechanical complications.

    Results: Flaps were raised in 18 patients. Two implants in 2 patients did not reach the planned inser- tion torque and were immediately replaced by larger diameter ones. Four months after loading, no drop-out or implant failure occurred. One biomechanical complication occurred in the all-on-2 group versus 4 in the all-on-4 group. There were no statistically significant differences between groups for complications. There were no differences between centres.

    Conclusions: These very preliminary results, just 4 months after loading, suggest that immediately loaded mandibular cross-arch fixed dental prostheses can be supported by only 2 dental implants. Longer follow-ups (around 10 years) are needed to understand whether cross-arch mandibular pros- theses can be successfully supported by only 2 dental implants.

    Conflict-of-interest statement: This study was completely self-financed and no funding from the implant manufacturers was sought or obtained, not even in the form of free materials.


    • ALL-ON-6    (8 ORE)



    • ALL-ON-2 INF.
    • ALL-ON-4 SUP.