Anitua E, et al. - In this trial, the experts evaluated the influence of immediate loading and lengths of splinted implants on the clinical efficacy of 6.5-mm-long implants that support two-implant fixed prostheses in the premolar-molar regions. The survival of the implants was not endangered by the immediate loading of short (6.5-mm-long) implants in the premolar-molar regions. Whether extra-short implants were splinted to another extra-short implant or to a longer one, two-implant supported prostheses had the same clinical effectiveness.