Clinical and Radiographic Follow-Up of Full-Arch Implant Prosthetic Rehabilitations: Retrospective Clinical Study at 6-Year Follow-Up

Aim: the aim of this retrospective clinical study was to evaluate clinically and radiographically full-arch implant prosthetic rehabilitations supported by six axial implants or four implants placed according to the All-on-Four protocol. Materials and methods: Patients in need of immediately loaded full-arch implant prosthetic rehabilitations of one or both arches were considered. Follow-up visits were performed one week after surgery, at 3 and 6 months and then once a year for the next 6 years to record implant survival, peri-implant parameters, marginal bone loss, bone cortical thickness and possible muscular, articular and prosthetic complications. A satisfaction evaluation questionnaire was also made available to all patients at the end of the follow-up period. Results: A total of 30 patients with total edentulism of one or both arches or need for avulsion of residual impaired teeth were enrolled for this study and underwent implant prosthetic rehabilitation on four or six implants. The overall implant survival rate at the six-year follow-up was 98.09%. Statistical analysis revealed a significant association between implant site and higher plaque and bleeding index in the posterior site. The extent of keratinized tissue was statistically superior in anteriorly located implants. Statistical analysis showed a significant difference between the values of bone-marginal levels as a function of time. The vestibular and palatal/lingual bone cortices were preserved, with an increasing trend in the apical direction. Regarding muscular and articular complications, the results of this study showed statistically significant differences between the mean values recorded in male and female subjects, while the most frequently encountered problems during the clinical evaluation were the presence of joint clicks and pain in the masseter muscles. Two of the patients examined showed problems with mandibular latero-deviation and prosthetic fracture. Conclusion: within the limitations of the present study, immediate implant-retained prosthetic rehabilitations supported by six axial implants or four fixtures placed according to the All-on-Four method could represent a valid therapeutic alternative to provide edentulous patients with restoration of masticatory function and aesthetics and promote their acceptance.