Short Implant and Heavy Smokers as Predictors for Failure of Immediate Implants: a Retrospective Study.

Background: The possibility of installing implants in fresh sockets was first proposed as a viable treatment option in the 1970s. Objective: to assess the relationships of subject-level and implant-level characteristics on the failure of immediate implants installed in sites that contained teeth associated or not with chronic apical periodontitis. Material and Methods: A retrospective study was undertaken with data from patients who received immediate implants with a minimum follow-up of 12 months after loading. The Generalized Estimating Equation, applying a multiple logistic regression model, was employed to investigate the association between predictor variables/co-variables and failure of the immediate implants. Results: Four hundred and twenty-three implants were installed (208 uninfected/215 infected sites) in 186 patients (92 men/96 women) with a mean age of 57.1 years old. The survival rate of implants was 91%. Approximately half (215/50.8%) of the alveoli that received immediate implants had chronic apical periodontitis associated with the extracted teeth, and 191 (88.8%) of these survived until the last follow-up visit. When the infection-free sites were analyzed, this frequency was higher (93,3%), but the presence of chronic apical periodontitis did not show statistical significance in the implant failure ( Conclusions: Short implants and consumption of more than 20 cigarettes/day were important predictors for failure of immediate implants, regardless of presence of chronic apical periodontitis.