Abstract
Dental implants have been widely used with success, but long-term usage sometimes leads to implant loss. The purpose of this review was to summarize the etiology of early and late failure requiring dental implant removal and the treatment strategies for the removal of failed implants and reimplantation. Early failures are often caused by patient-related factors, such as smoking, diabetes, radiotherapy, bone quality, and periodontitis of the remaining natural teeth. The most common cause of late failure is peri-implantitis, followed by implant fracture and implant malpositioning. Implants should be removed if they are mobile or if their superstructure cannot be maintained (e.g., implant fracture). For peri-implantitis, implant removal should be determined based on the patient's age and esthetic needs, the implant site, and the severity of bone loss. Many reports have been published on implant removal techniques. The reverse torque technique should always be the first choice because of its low invasiveness. The weighted survival rate for the replacement of failed implants is 86.3%, with a much lower survival rate after the second or subsequent implantations. Therefore, patient-specific problems, such as smoking habits and bruxism, should be checked before reimplantation and controlled to the greatest extent possible.