Purpose: This overview aimed to answer the following research question: What is the current knowledge regarding the performance of the "All-on-Four" technique compared to other full-arch implant rehabilitation methods based on evidence from systematic reviews?
Methods: This overview assessed the performance of the "All-on-Four" concept versus other implant-supported full-arch rehabilitation techniques. Outcomes included implant number, loading protocol, marginal bone loss (MBL), and cumulative survival rate (CSR). The protocol was prospectively registered in PROSPERO (CRD42023471446). A comprehensive search was performed across ten databases, including grey literature. Methodological quality was assessed using AMSTAR-2, and risk of bias was evaluated with ROBIS. Two reviewers independently conducted all steps, with a narrative synthesis of results.
Results: A total of 4,468 records were identified, and eight systematic reviews published between 2013 and 2021 were included. For the "All-on-Four" technique, CSR ranged from 94.8% to 99.3%, and mean MBL ranged from 1.1 mm to 1.5 mm. None of the reviews reported statistically significant differences suggesting the "All-on-Four" protocol is inferior to approaches with more implants. However, most reviews showed a high risk of bias and low methodological quality.
Conclusions: "All-on-Four" technique demonstrates clinical outcomes comparable to conventional full-arch rehabilitations, but evidence is limited by methodological weaknesses.
Keywords: Dental Implant; Dental Prosthesis; Implant-Supported; Osseointegrated Implants.
© 2025. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.