Key points
- A full arch of fixed teeth is carried on four implants (sometimes six). The back implants are usually tilted, to use the bone that is there and avoid the sinus.
- In many cases a fixed temporary bridge is fitted within days of surgery, and the final bridge follows months later.
- In a study of 1,072 patients followed for 5 to 13 years, 94.7% of the implants survived and 99.2% of the bridges stayed in function.
- Smoking and male sex were linked to a higher risk of implant failure in that study.
What it is
All-on-4 is a way of replacing all the teeth in one jaw with a fixed bridge — not a removable denture — carried on four implants. Two are placed upright at the front; the two at the back are tilted, so that longer implants can be anchored in the bone that is available without entering the sinus. Where the bone allows, six implants may be used instead of four.
Who it is for
People who have lost all the teeth in a jaw, or whose remaining teeth cannot be saved and will be extracted as part of the treatment. Whether the bone is enough is decided from the CT scan.
How the treatment goes
Extractions, if needed, and the implants are usually done in one operation. In many cases a fixed temporary bridge is attached within days — this is called immediate function — so the patient is not left without teeth. After a few months of healing the final bridge is made and fitted.
What the research shows
Maló and colleagues (2019) followed 1,072 patients with 4,288 upper-jaw implants placed this way, for 5 to 13 years. The cumulative implant survival was 94.7%, and the bridges stayed in function in 99.2% of patients. Average bone loss around the implants was 1.18 mm at 5 years and 1.67 mm at 10 years.
Male sex and smoking were associated with implant failure; smoking was also associated with more bone loss. This matches the wider research on smoking and implants.
Worth knowing
- The long-term figures come largely from the clinic that developed the concept, and one patient in five was lost to follow-up — independent long-term data is thinner.
- In the same study, biological complications (inflammation around the implants) affected 7.8% of implants.
- A full-arch bridge needs regular check-ups, professional cleaning and occasionally repairs. It is not a one-time treatment.
Sources
- Maló P, de Araújo Nobre M, Lopes A, Ferro A, Nunes M. The All-on-4 concept for full-arch rehabilitation of the edentulous maxillae: a longitudinal study with 5-13 years of follow-up. Clin Implant Dent Relat Res. 2019;21(4):538-549.
- Chrcanovic BR, Albrektsson T, Wennerberg A. Smoking and dental implants: a systematic review and meta-analysis. J Dent. 2015;43(5):487-498.
This summary is general information and no substitute for an examination and personal medical advice. The figures are averages from studies, not a promise of a result.