Causes of Implant Failure and Subsequent Removal: A Retrospective Study in a Hospital Setting

To evaluate the causes and risk factors associated with implant removal as observed in a hospital setting over a 20-year timespan to find the most common causes leading to implant removal.

In the present retrospective study, implants removed between 2000 and 2022 were registered and the cause of removal established. All implants were removed by a single operator (P.P.M.) in the Department of Oral Surgery of the George Eastman Dental Hospital in Rome, Italy. Characteristics of removed implants such as implant surface, morphology (bone- versus tissue-level implants), type of restoration (fixed versus removable), mode of retention in the case of fixed restorations (cement- versus screw-retained), and location of the implant (maxillary versus mandibular) were recorded. Patient-level characteristics were also recorded, including patients' systemic health conditions, the medications they were currently taking or had taken, smoking habits, and if they had a previous history of periodontitis.

In total, 381 implants in 381 patients were removed in the 20-year timespan. The most frequent cause of removal was peri-implantitis (82.4% of implants), followed by implant malposition and loss of osseointegration.

The survival time was not affected by the cause of removal, while bone-level implants had a longer survival time versus tissue-level implants. Maxillary implants had a higher prevalence of peri-implantitis compared to mandibular implants.