Implant Body Fracture Due to Fatigue in a Maxillary Implant-Retained Overdenture Treatment.

The aim of this study was to determine the causes of fatigue and implant failures in an implant-retained overdenture case. One out of four implants portrayed inadequate osseointegration during healing abutment placement, and one was fractured from the middle to the apical third after 1 year of denture use. Various aspects, such as insufficient cooling while implant socket preparation, incorrect prosthodontic planning, and erroneous design of the denture, were evaluated. Macroscopic and microscopic inspections of the fractured implant body were assessed by scanning electron microscopy (SEM) and optical microscopy. Consequently, metallic fatigue along with secondary cracks and beach marks were evident. It was deduced that the failed and fractured implants depicted substandard osseointegration; thus, they were susceptible to the wear out effect of the occlusal forces. Unfavorable osseointegration caused the fulcrum axis to move apically instead of forming on the neck part of the implant, and micromovements around the fulcrum axis mustered the fracture.