Factors influencing the failure of dental implants: A systematic review

Currently, dental implants are considered useful alternatives to missing teeth, although they may suffer from failure. In this study, the current scientific literature has been reviewed to highlight the risk factors affecting dental implant failure. Radiotherapy in the neck and head cancers, diabetes, smoking, osteoporosis, and HIV can increase the occurrence of risk factors for the failure of a dental implant. As a result of negative impacts on osseointegration, osteoporosis, smoking, and head, neck radiotherapy causes a higher risk of dental implant failure. The irradiation target volume during radiotherapy is the main cause of implant failure, especially due to the increment of marginal bone resorption. Additionally, the healing of bones around dental implants is negatively affected by heavy smoking due to the reduction of the healing speed. Moreover, diabetic patients have some complications (e.g., delayed wound healing of soft tissues, periodontitis, impaired response to infection, tooth loss, and microvascular disease) affecting therapyial preliminary considerations of dental implant treatment. However, in case of HIV-positive patients, the dental implant failure rate would not increase due to affective factors (e.g., prophylactic antibiotic treatment, the administration of active antiretroviral therapy, and control of the CD4+ T lymphocyte counts). Therefore, these patients have no clinical signs of mobility or infection in this treatment and much more attention should be paid to these patients and they should be treated with controlled oral surgical procedures.