Abstract Objectives: The aim of this systematic review was to evaluate the best timing for placing implants after tooth extraction, by comparing early vs. delayed implant placement and evaluating the hard and/or soft tissue ridge dimensional changes and the outcomes related with implant survival and prosthesis success. Results: Eight studies were included, although meta-analysis could only be performed with the data from two studies comparing early vs. delayed implant. The percentage of bone height and bone width reduction favoured the early placement, with pooled mean difference between groups of 13.11% (95% CI: from 3.83 to 22.4; P = 0.057) and 19.85% (95% CI: from 13.85 to 25.81) respectively. Implant survival demonstrated a non-significant higher implant survival rate for the early group (RR = 1.02, 95% CI: 0.96-1.1).With regard to patient satisfaction, statistically significant differences between the groups in favour of the early group for overall satisfaction and appearance with the restoration were demonstrated at 2 years, although these differences were lost at 5 years
