Immediate versus Conventional Loading of Post-Extraction Implants in the Edentulous Jaws

PurposeThis retrospective study deals with the issue of how to realize the transition from a failing dentition to an implant-supported prosthesis. The main aim was to assess the reliability of immediate implant and immediate loading (IL) protocols in the edentulous jaws. A further aim was to investigate the role of patient-related, implant-related, and surgery-related secondary variables in the occurrence of implant failure. Materials and MethodsPatients with at least a 4-year post-loading follow-up undergoing the transition from a failing dentition to an implant-supported prosthesis were retrospectively investigated. Primary variables of implant failure were immediate placement and IL. Secondary variables were categorized as demographic, anatomic, site, and prosthetically related. Cumulative survival rates (CSRs) were compared using the Kaplan-Meier survival estimate method. Predictors of failure were included in a multivariate Cox regression model to evaluate the simultaneous effects of multiple covariates and control for correlated observation. Crestal bone loss was also measured at the delayed and the immediately loaded implants. ResultsFive hundred nineteen implants rehabilitating 91 jaws in 80 patients were followed. The Kaplan-Meier survival estimate method showed that immediate implant and IL decreased the CSR significantly in the maxilla but not in the mandible. Some secondary variables were found to affect the CSR: maxillary location, age over 70 years, prostheses supported by only immediate implants or a majority of them, temporary cementation, implant diameter, and length. Crestal bone loss was not significantly related to the outcomes. ConclusionsThe present data may provide clinical recommendations to the practitioner treating the transitional patient. In the mandible, the use of immediate implants and IL does not increase the failure rate. In the maxilla however, combining immediate placement and IL may significantly increase the failure rate.