Seventeen prospective (n=1,216 implants) and 17 retrospective (n=2,623 implants) studies were included. Mean follow-up, where reported, ranged from 13 to 84 months for prospective studies and from 15 to 96 months for retrospective studies. Most of the included studies were rated unknown quality or fair quality. Most studies reported only on implant survival.
In prospective studies, mean loss of immediately placed implants was 6.2% (range 0 to 40%, SD 10%) and that of early placed implants was 3.6% (range 0% to 6.4%). In retrospective studies, mean loss of immediately placed implants was 3.5% (range 0 to 14.8%, SD 4.1%). Pooled weighted mean survival rates and 95% CIs were presented graphically and appeared to be slightly higher for immediate and delayed implants than for early implants; however, no numerical values were reported.