Post-extraction implant placement into infected versus non-infected sites : a multicenter retrospective clinical study

Purpose: The aim of this study was to assess whether immediate implant placement into post-extraction sites presenting a chronic infection poses a greater risk of implant failure than immediate placement in non-infected sites. Materials and Methods: Records of patients who underwent extraction and immediate implant placement into both infected and non-infected sites from January 1998 to September 2014 at 5 different dental centers were considered for inclusion. Included records were subjected to statistical analysis of survival rates, along with a number of other patient-, implant-, surgery-, and prosthesis-related variables. Results: The inclusion criteria were met by 369 patients who received a total of 527 implants. The follow-up averaged 53.2 months (range 0.9-158.3) for implants placed into non-infected sockets (N = 334) and 50.1 months (range 1.6-146.1) for those placed into infected sites (N = 193). Seven implants failed in non-infected sites and 3 in infected ones. All failures occurred within 1 year of placement. Cumulative implant survival rate for non-infected and infected sites was, respectively, 97.9% ± 0.8% and 98.4% ± 0.9%, being not significantly different (P =.66). None of the investigated variables affected the outcome. Conclusions: Placement of implants into periodontally or endodontically infected sites immediately after tooth extraction is a safe option, even when the implants are loaded immediately or early.