Aim: To assess the outcome of immediate or early placement of implants after tooth extraction supporting a single-tooth restoration with focus on the marginal bone level and its stability over time. Material and methods: An electronic literature search without time restrictions was conducted of the Medline/PubMed database accompanied by a handsearch. Clinical human studies reporting on periimplant marginal bone level (BL) and/or changes in bone level (BLC) and with a follow-up period of at least 12 months were selected for the present review. Results: The search strategy resulted in 816 articles and 115 relevant publications were included for full-text analysis. Only few randomised controlled trials exist comparing immediate or early implant placement with placement in healed bone (the conventional protocol). Summarising the results from prospective studies, it was found that the mean marginal bone loss around immediately or early placed implants from baseline (at implant placement or placement of restoration) to the latest followup visit (between 1 and 10 years) was less than 1.5 mm. Conclusion: The current literature indicates that immediate or early placement of single-tooth implants after tooth extraction may be a viable treatment with long-term survival rates and marginal bone level conditions matching those for implants placed conventionally in healed bone ridges. Schlagwörter: dental implant, long-term, marginal bone level, outcome, review, timing