Review suggests higher failure rates for dental implants placed in fresh extraction sites

Abstract

PubMed, Web of Science and Cochrane Oral Health Group Trials. Register databases supplemented by hand searching a range of dental implants-related journals. Randomised and non-randomised studies comparing implant failure rates in any group of patients receiving dental implants being inserted in fresh extraction sockets compared to the insertion in healed sites were considered. Study quality was assessed using the Newcastle-Ottawa scale (NOS). Implant failure (complete loss of implant) and postoperative infection were the dichotomous outcomes measures evaluated, with marginal bone loss as a continuous outcome. Seventy-three publications were included, five were randomised controlled trials, 26 clinical controlled trials and 42 retrospective studies. The 73 studies included a total of 8241 dental implants inserted in fresh extraction sockets, with 330 failures (4.00%), and 19,410 implants inserted in healed sites, with 599 failures. A random effects meta-analysis (73 studies) found the relative risk of implant failures in fresh socket sites compared to healed sites was RR= 1.58 (95% CI; 1.27 1.95) for the maxilla only RR= 1.61 (95% CI; 0.97 2.66); mandible only RR= 2.15 (95% CI; 0.62-7.47). For implants supporting single crown restoration RR= 2.05 (95% CI; 1.36-3.11) and RR= 1.42 (95% CI; 0.71- 2.83) for those with a full arch prosthesis.There were 31 controlled studies (CCTs) and randomised controlled studies (RCTs) that included 2021 implants inserted in fresh sockets with 96 failures (4.75%) and 2759 implants were inserted in healed sites with 49 failures (1.59%). The relative risk of implant failures in fresh socket sites compared to healed sites was RR= 2.27 (95% CI; 1.57-3.29). The results of the present review should be interpreted with caution due to the presence of uncontrolled confounding factors in the included studies, most of them not randomised trials. Within the limitations of the existing investigations, the present study suggests that the insertion of dental implants in fresh extraction sockets affects the implant failure rates.