Clinical outcomes of full‐arch immediate fixed prostheses supported by two axial and two tilted implants: A retrospective cohort study with 12–15 years of follow‐up.

Purpose: To retrospectively assess clinical and radiographic outcomes of immediately loaded full‐arch fixed prostheses supported by axial and tilted implants up to 15 years of function. Materials and Methods: Patients with one completely edentulous arch received an immediate full‐arch fixed prosthesis supported by two anterior axial and two posterior tilted implants. Definitive prosthesis consisting of a CAD‐CAM titanium framework and acrylic teeth was delivered 6 months later. Patients were regularly followed to assess clinical parameters and marginal bone level (MBL) change. Multilevel regression analysis was performed to investigate factors affecting implant failure and MBL. Results: Six hundred ninety‐two implants were placed in 72 maxillae and 101 mandibles. Seven maxillary implants (5 axial and 2 tilted) in 6 patients and 12 mandibular implants (6 axial and 6 tilted) in 5 patients failed. 15‐year cumulative implant survival was 97.51% and 96.91% in maxilla and mandible, respectively (p =.64). After 10 years, the difference in MBL between axial and tilted implants was not significant in the maxilla (p =.47, 65 patients), while it was in the mandible (p <.001, 80 patients). Significant higher bone loss was reported in the mandible at both 5‐ and 10‐year follow‐up (p <.001 and p =.004, respectively). Mixed‐effect multilevel linear regression evidenced a correlation between arch and bone loss at 5‐ and 10‐year follow‐up, while no correlation was found with age, gender, smoking, diabetes, and history of periodontal disease. Conclusion: This long‐term study suggests that the present technique can be considered a viable treatment modality for the immediate rehabilitation of both maxilla and mandible. [ABSTRACT FROM AUTHOR]