PURPOSE: To establish the outcomes and their reproducibility for the
All-on-4® treatment protocol for full arch edentulism.
MATERIALS AND METHODS: A retrospective observational cohort study of patients
treated at a surgical private practice. Primary outcomes
were three year cumulative implant and prosthesis
survival. Secondary outcomes were surgical or prosthetic complications not resulting in implant or prosthesis loss. Marginal bone loss, measured on standardized
panoramic radiographs was recorded if the loss exceeded Albrektsson’s standards (less than 1 mm in the first
year and maximum of 0.2 mm per year thereafter).
RESULTS: Twenty-five patients (15 women, 10 men) were reviewed, with 124 implants supporting 31 full-arch fixed prostheses. Twenty had greater than three year follow-ups
(range 40.7 – 139.7 months, mean 96.9 months), comprising 96 implants, and 26 jaws. Three implants failed
in two patients, (survival rate 97.9%). One prosthesis
failed (96.2% survival rate). Two patients required prosthesis replacement due to implant loss. One abutment
screw fractured, which required replacement. A total of
seven implants, in four different patients, had marginal
bone loss in excess of the Albrektsson norm.
CONCLUSION: This study found that the reliability and predictability of
the All-on-4® concept is verifiable for the treatment of