Restoration of the Atrophic Maxilla with Four Narrow and Ultrashort Implants

Abstract

Presented is a prospective cohort study of 72 calcium phosphate coated Bicon Integra-CP implants for 18 patients with pronounced class V and VI maxillary atrophy according to the classification of Cawood and Howell (1988) and treated with four ultrashort 4.0 x 5.0 mm locking taper implants. The patients were divided into three groups. For the first group, four 4.0 x 5.0 mm implants were placed. For the second group, two narrow 3.0 x 8.0 mm implants were placed in very thin anterior alveolar bone. For the third group, the alveolar bone in the premolar and molar region was too narrow and too shallow; therefore, 4.0 x 5.0 mm implants were placed in the maxillary tuberosities. All implants were restored with TRINIA, a metal-free fiber-reinforced hybrid resin CAD/CAM material. Two patients lost one implant each during the observation period, which were subsequently replaced successfully. The cumulative one-year patient-based implant survival rate (CSR) was 88.8%. The cumulative one-year implant-based survival rate was 97.2%. Since the patients with a failed implant were able to wear their prosthesis with only three implants while the replacement implants were being osseointegrated, this resulted in 100% prosthetic success. The good result allows the conclusion that the long-term use of four ultrashort and narrow locking taper implants reveal a comparable outcome to standard size implants with complex bone augmentations.