Three-year evaluation of four short implants supporting full-arch fiber-reinforced prostheses in severely atrophic maxillae

This paper reports the 3-year outcomes and provides data on fiber-reinforced prostheses supported by four short implants (sizes 3.0 x 8.0 mm and 4.0 x 5.0 mm) in severely atrophic maxillae. A prospective temporal cohort study was designed for a total of 18 patients with severely atrophic maxillae corresponding with Cawood and Howell's class V and VI classifications, and a total of 72 implants were placed. The patients were divided into three groups. Patients in the first group each received four 4.0 x 5.0-mm Integra-CP implants (Bicon). Patients in the second group had very thin anterior maxillae and received two 3.0 x 8.0-mm implants. The third group comprised patients whose premolar alveolar bone had minimal height and was also too thin to split, so these patients received two 4.0 x 5.0-mm implants in their tuberosities. All patients received a cement- or screw-retained CAD/CAM-produced metal-free fiber-reinforced hybrid resin prosthesis. Three patients each lost one implant, and all missing implants were replaced. The patient-based 1- and 3-year cumulative survival rates (CSRs) were 94.7% and 81.4%, respectively. The implant-based 1- and 3-year CSRs were 98.7% and 95.1%, respectively. Because all three of the patients who lost an implant continued to use their prostheses during the osseointegration of the new implant, there was a 100% prosthetic success rate.