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Digital impressions for fabrication of definitive "all-on-four" restorations
Enrico Felice Gherlone1, Francesco Ferrini, Roberto Crespi
1*Full Professor and Chairman, Department of Dentistry, Vita Salute University, IRCCS San Raffaele, Milan, Italy. †Private Practice, Frascati, Rome, Italy. ‡Clinical Professor, Department of Dentistry, Vita Salute University, IRCCS San Raffaele Hospital, Milan, Italy. §Associate Professor, Dental School, University of Brescia, Brescia, Italy. ‖Adjunct Professor, Department of Dentistry, Vita Salute University, IRCCS San Raffaele, Milan, Italy.
Purpose:
The aim of this study was to assess the accuracy of digital impressions for "all-on-four" implant rehabilitation.
Materials And Methods:
Patients edentulous in one or both jaws were randomly selected for this study. Complete arch immediately loaded prostheses supported by 4 implants (2 axial and 2 tilted) were placed. Five hours after implant placement, screw-retained full-arch temporary prostheses were positioned. After 4 months, a digital scan body was used to finalize definitive prosthesis. Radiographic assessments were obtained immediately after surgery and at each follow-up visit. Bone level measurements were reported at 6 and 12 months, and bone loss between upright and tilted implants was compared.
Results:
Fourteen definitive cast metal frameworks prosthesis were delivered to the patients. No implant dropout occurred. All prosthesis were screwed onto the dental implants, and x-ray examinations revealed a bar-implant connection accuracy. The implant survival rate was 100% for all positioned implants. No statistically significant differences (P > 0.05) in crestal bone loss between tilted and upright implants were detected.
Conclusions:
Digital impression creates an accurate physical model significantly improving efficiencies for the dental team and streamlining the workflow.
