Impacted Teeth vs Immediate Post-extraction Implants: A Review of Survival, Marginal Bone Loss, and Complications

Dental implant therapy increasingly emphasises shortening treatment time and minimising surgical morbidity while maintaining long-term biological stability and esthetic integration. Two approaches that aim to reduce or avoid extensive hard-tissue surgery are (i) implant placement through impacted teeth or retained dental tissues (hereafter, “transdental” placement) and (ii) immediate post-extraction implant placement in fresh sockets. Although both strategies may reduce the number of surgical stages compared with conventional delayed placement, they arise from different clinical problems: transdental placement is typically considered when an impacted tooth obstructs the ideal implant trajectory and surgical removal would create substantial defects, whereas immediate placement addresses replacement of a failing or hopeless tooth at the time of extraction. This review synthesises contemporary evidence on survival, marginal bone loss, and complications for each approach, and interprets these outcomes through a biological and risk-management lens. Current human data indicate that implants placed through impacted teeth can achieve high short- to medium-term stability in carefully selected cases, but the evidence base remains dominated by small case series and heterogeneous follow-up. Immediate post-extraction implants demonstrate high overall survival in systematic reviews and randomised trials, though slightly lower survival than delayed protocols have been reported in some meta-analyses, and esthetic complications remain a key concern in thin phenotypes or compromised sockets. Across both approaches, outcomes appear highly dependent on case selection, meticulous imaging-based planning, primary stability, infection control, and soft-tissue management. Robust comparative studies with standardised radiographic and patient-reported outcomes are needed before transdental placement can be recommended beyond narrowly defined indications.