Implants in the Posterior Maxilla: Open Sinus Lift Versus Conventional Implant Placement. A Systematic Review

To compare implant survival, marginal bone loss, peri-implant clinical parameters, and complications in dental implants placed in the posterior maxilla in native bone or after grafting using the open sinus lift technique.

A search was made of two electronic databases (MEDLINE via PubMed and the Cochrane Oral Health Group Trials Register [CENTRAL]), complemented by a manual search. The study included randomized clinical trials, non-randomized clinical trials, and observational studies such as cohort studies and case-control studies conducted on a prospective or retrospective basis and comparing the placement of standard length implants (≥ 10 mm) in native bone or after grafting using the sinus lift procedure. Risk of bias was evaluated with the Cochrane risk of bias assessment tool and the methodological index for non-randomized studies (MINORS).

The search yielded 90 studies, of which 23 were included. Two studies were evaluated with the Cochrane risk of bias assessment tool, with neither being identified as presenting low risk of bias. Twenty-one studies were evaluated by the MINORS, yielding a mean score of 15.66 points out of 24. The implant survival rate in the control group was 90% to 100% versus 75.3% to 100% in the test group over a follow-up period of 6 to 120 months. Most studies revealed no statistically significant differences. In most of the publications, marginal bone loss was greater in the test group than in the control group, though without reaching statistical significance. Similar results were obtained in both groups with regard to the peri-implant clinical parameters. There were more surgical complications in the test group than in the control group-such complications being inherent to the sinus lift procedure.

Implant placement after sinus lift affords results in terms of implant survival, marginal bone loss, and peri-implant clinical parameters similar to those obtained with conventional implant placement in native bone. However, there is a greater incidence of surgical complications associated with the sinus lift procedure.