A randomized clinical trial in “All on four” rehabilitations with 6-years follow-up: digital versus traditional workflow

Aim The present study compares and evaluates the “All on Four” type rehabilitations obtained through a traditional technique, with “All on Four” rehabilitations made using an entirely digital method, with a 6-years follow-up. Materials and methods The workflow displayed in this study analyzes in detail each design and clinical phase of both methods, which were applied to a total of 50 patients recruited by the Department of Dentistry of the University Vita e Salute San Raffaele. The selected patients were divided into two randomized groups of 25 people: in total, 100 implants were placed in 25 patients who received a full-arch rehabilitation performed using the traditional All on Four method and 100 implants in 25 patients who received a full-arch rehabilitation performed using a digital method. After 6 years, different percentages of success were obtained: 98% of success for the group of patients treated with the traditional "All on Four" protocol and 100% of success for the group treated with the digital protocol. At each time interval a significant difference (P <0.0001) in peri-implant crestal bone loss between the two groups was detected, with an average Marginal Bone Level (MBL) at 6 years of 1.12 ± 0.25 mm in patients treated with traditional method and 0.88 ± 0.10 mm in patients treated with digital method. Patients belonging to the digital group have judged the immediate loading (92%), digital smile preview (93%), the mock-up test (98%) and guided surgery (94%) as very effective. All patients treated with a digital method reported a lower value of during-surgery and post-surgery pain compared to patients rehabilitated using traditional method. Conclusion The totally digital protocol described in the present study represents a valid therapeutic alternative to the traditional “All on Four” protocol for implant-supported rehabilitations of edentulous dental arches.