There is insufficient evidence to determine possible advantages or disadvantages of immediate, immediate-delayed or delayed implants, therefore these preliminary conclusions are based on few underpowered trials often judged to be at high risk of bias. There is a suggestion that immediate and immediate-delayed implants may be at higher risks of implant failures and complications than delayed implants on the other hand the aesthetic outcome might be better when placing implants just after teeth extraction. There is not enough reliable evidence supporting or refuting the need for augmentation procedures at immediate implants placed in fresh extraction sockets or whether any of the augmentation techniques is superior to the others.
Immediate placement of implants in periapical infected sites: a prospective randomized study in 50 patients.
To determine clinical success when implants are placed in chronic periapical infected sites.
                Fifty patients (25 females, 25 males, mean age 39.7 +/- 14.5 years) were included in this prospective controlled study. After randomization, 25 Frialit-2 Synchro implants were immediately placed (IP) after extraction, and 25 Frialit-2 Synchro implants were placed after a 3-month healing period (DP). Thirty-two implants were placed in the anterior maxilla and 18 implants were placed in the premolar region. Implant survival, mean Implant Stability Quotient (ISQ) values, gingival aesthetics, radiographic bone loss, and microbiologic characteristics of periapical lesions were evaluated for both groups.
                Overall, 2 implants belonging to the IP group were lost, resulting in a survival rate of 92% for IP implants versus 100% for DP implants. Mean ISQ, gingival aesthetics and radiographic bone resorption, and periapical cultures were not significantly different with the IP and DP implants.
                Immediate implant placement in chronic periapical lesions may be indicated.