This critical summary was conducted to achieve an evidence based decision about immediate implants supporting full arch fixed prostheses (FAFP). A randomized clinical trial (RCT) comparing periimplant health, radiographic outcomes and success of immediate versus delayed implants, supporting FAFP was selected and critically appraised by Cochrane tool for risk assessment of bias. In the RCT, a one-year follow up showed no significant difference between both treatment modalities regarding all clinical and radiographic outcomes, except for crevicular fluid volume in maxilla, which was 87.4 ± 60.5 for immediate and 34.7± 22.6 for delayed implants (p<0.05). Selection, co-intervention, assessment and attrition biases are highly suspected. Considering the biases that might be introduced in this trial, evidence about the results could be limited. Therefore, immediate implants are recommended limitedly based on proper case selection. RCTs with calculated sample sizes, standardized treatment and measurement procedures are still highly required to enhance the internal validity.