Background: The aim of this case series was to evaluate the 5-years clinical and radiographic outcomes of immediate full-arch fixed prosthesis supported by a novel implant system characterized by a low-speed site preparation protocol.

Methods: Six medically compromised patients (3 females and 3 males) were consecutively enrolled and treated. Each patient received a fixed full-arch rehabilitations supported by two axial and two tilted implants. A total of 24 implants (N1 System, Nobel Biocare AB, Göteborg, Sweden) were placed in three mandibles and three maxillae using a low-speed drilling protocol with no irrigation. Prosthetic loading was applied within 2 hours of surgery, while then definitive restorations were placed 4 months later. Patients were scheduled for follow-up every 6 months up to 2 years and then annually. Radiographic evaluation of marginal bone level change was performed on regular intervals.

Results: Between February 2019 and July 2019, six patients received a full-arch fixed prosthesis on four implants. All implants reached a minimum insertion torque of 30 Newton for immediate loading. After 5 years of observation (range 62-67 months), no implants failed and all definitive prostheses were stable and functional, resulting in a cumulative survival rate of 100%. After 5 years, the marginal bone loss was 1.46 ± 0.16 mm for the mandible and 1.85 ± 0.18 mm for the maxilla. Two implants (one axial and 1 tilted) in 1 patient treated in the maxillary arch reported more then 2 mm of marginal bone loss after 5 years.

Conclusions: Within the limitations of this study, the successful medium-term results seem to confirm that immediate fixed full-arch rehabilitation, supported by two anterior axial and two posterior tilted implants, could be an effective and biologically beneficial treatment for complete arch edentulism. The reduced bone remodeling evidenced after 5 years of function confirm the biologically friendly concept behind this novel implant system.