Randomized controlled multicenter study comparing short dental implants (6mm) versus longer dental implants (11-15mm) in combination with sinus floor elevation procedures: 5-year data.

Aim To compare the implant survival rate between short dental implants and standard length implants placed in combination with bone grafting at 5 years of loading. Methods This multicentre study enrolled 101 patients (137 implants) with a posterior maxillary bone height of 5-7 mm. Patients randomly received either short implants (6 mm; GS) or long implants (11-15 mm) with sinus grafting (GG). Six months later, implants were loaded with single crowns and patients re-examined at 1, 3 and 5 years of loading. Outcomes included: implant survival, marginal bone levels (MBLs), biological and technical parameters and patient-reported outcome measures (OHIP-49 = Oral Health Impact Profile). Statistical analysis was performed using a non-parametric approach. Results At 5 years, 90 patients (124 implants; GS: 60; GG: 64) were re-examined (drop-out rate 10%). Patient-level implant survival rates were 98.5% (GS; 1 implant failure) and 100% (GG; p = 0.49). Mean MBLs were 0.54 mm +/- 0.87 (GS) and 0.46 mm +/- 1.00 (GG; p = 0.34). Biological and technical parameters were not significantly different (p > 0.05). Median overall OHIP-49 scores improved significantly up to 5 years in both groups (GS: p = 0.03; GG: p = 0.00; intergroup comparison p = 0.11). Conclusions Both treatment modalities were suitable for implant therapy in the atrophied posterior maxilla revealing no differences in terms of survival rates, marginal bone levels (changes), patient-reported outcomes and technical/biological complications.