Immediate loading of four or six implants in completely edentulous patients.

In this retrospective study, 44 patients received screw-retained full-arch acrylic resin provisional prostheses connected on 4 or 6 implants in the mandible or maxilla, respectively. With a mean follow-up of 17.6 months, 3 of 205 implants were lost and replaced successfully. Cosmetic fractures were shown in six patients; one abutment loosening, one abutment fracture, and one implant fracture were also observed. Prosthetic fracture was shown in one patient. Marginal bone loss reached two to five threads on 13 implants (6.4%). The results confirmed that immediate loading of 4 mandibular or 6 maxillary implants with an acrylic resin prosthesis for full-arch rehabilitation is a reliable technique in the short- and midterm.