Oral rehabilitation through dental implants is a fundamental solution for restoring the quality of life in edentulous patients and has been widely used due to its high success rates. The all-on-four concept combines two anterior axial implants and two posterior angled implants, making it a viable rehabilitation option for patients with severe bone loss, minimizing the complexity of the surgical procedure, and enabling immediate rehabilitation. Although it presents excellent success rates, it is important to understand the risk factors for implant survival failure. The aim of this work is to conduct a narrative review of the literature and, from it, analyze the failure rates of rehabilitations using the all-on-four protocol. The possible factors identified were gender, maxillary bone, smoking, presence of bruxism, systemic diseases, and previous periodontitis. The implant survival rate confirmed the high success rates of the technique, varying between 94% and 99%. Smoking was shown to be the main risk factor for failure, a variable present in all reviewed articles. The presence of bruxism also presented relevance, albeit more discreetly. The other factors did not show significant impact. It is concluded that there is a need for a greater number of randomized clinical trials with larger samples and long-term follow-up, as the current evidence is limited by the quality of available studies and the scarcity of data on longer clinical outcomes.