The prognosis of partial implant-supported fixed dental prostheses with cantilevers. A 5-year retrospective cohort study

Purpose: To report the outcome of implant-supported fixed partial prostheses with cantilevers at 5 years after loading. Material and methods: A total of 174 patients, 106 females and 68 males with 225 implants (maxilla: 149; mandible: 76), supporting 191 fixed dental prostheses (maxilla: 125; mandible: 66) were included. Inclusion criteria were patients rehabilitated with partial prostheses with cantilevers and sufficient amount of bone to place implants of at least 7 mm long. Primary outcome measures were prosthesis and implant success as well as biological and mechanical complications. The secondary outcome measure was pen-implant marginal bone loss. Results: Sixteen patients with 21 implants dropped out (9.2% of patients; 9.4% of implants). Three implants were lost in 3 patients. Two prostheses were lost rendering a survival estimation of 99.0% at 5 years (Kaplan-Meyer). Overall mean (standard deviation) bone level was 0.15 mm (0.34mm), 1.56mm (0.88 mm) and 1.88 mm (1.05 mm) at implant insertion, and 1 and 5 years after implant placement, respectively. The frequency at patient level of biological and mechanical complications was 2.9% and 27.6%, respectively. Conclusions: Within the limitations of this study, it is possible to conclude that it is viable to use fixed implant-supported partial rehabilitations with a cantilever, judging by the 99% prosthetic success rate at 5 years. However, there is a relatively high frequency of complications to cope with in these rehabilitations.