Aims: The aim of this prospective study was to evaluate and compare the implant survival rate,
marginal bone levels and prostheses failure rate, of three-unit fixed dental prostheses (FDPs)
supported by three vs. two implants immediately loaded in the posterior area.
Material and Methods: Partially edentulous patients in need of a three-unit implant supported FDP
in the maxillary/mandibular posterior region were recruited and randomly split into two groups:
Group 1 with three-unit FDP supported by three implants (Control); Group 2 with three-unit FDP
supported by two implants (Test). Implants were inserted and immediately loaded with a temporary
FDP. Results: Sixty-three patients were included in the study. A total of 178 implants were placed
and immediately loaded (128 maxillary/50 mandibular) to support 74 immediate provisional fixed
prostheses (52 maxillary and 22 mandibular) delivered on the same day of implant
insertion/placement; 30 in Group 1 and 44 in Group 2. The comparison of three vs. two implants
resulted in comparable implant survival rate, marginal bone loss, and prostheses failure rate.
All implants healed uneventfully with no adverse clinical and radiographical signs or symptoms
except for one implant failure in Group 1 resulting in a cumulative success rate of 99,5%, 98,9% for
Group 1 and 100% for Group 2 with a follow-up of 6-to-10 (mean 7 years). Once loaded, the implants remained
in function from a minimum of 6 years to 10 years. Conclusions: Although more studies and larger sample sizes
are needed to validate this study, the results showed no difference between the two Groups, demonstrating the
potential viability of both clinical options.
Keywords: Partially Edentulous, Immediate Loading, Posterior Rehabilitation, Implant fixed dental prostheses