BIOLOGICAL FACTORS CONTRIBUTING TO FAILURES OF OSSEOINTEGRATED ORAL IMPLANTS - (2) - ETIOPATHOGENESIS

The aim of the present review is to evaluate the English language lite rature regarding factors associated with the loss of oral implants. An evidence-based format in conjunction, when possible, with a meta-anal ytic approach is used. The review identifies the following factors to be associated with biological failures of oral implants: medical statu s of the patient, smoking, bone quality, bone grafting, irradiation th erapy, parafunctions, operator experience, degree of surgical trauma, bacterial contamination, lack of preoperative antibiotics, immediate l oading, nonsubmerged procedure, number of implants supporting a prosth esis, implant surface characteristics and design. Excessive surgical t rauma together with an impaired healing ability, premature loading and infection are likely to be the most common causes of early implant lo sses. Whereas progressive chronic marginal infection (peri-implantitis ) and overload in conjunction with the host characteristics are the ma jor etiological agents causing late failures. Furthermore, it appears that implant surface properties (roughness and type of coating) may in fluence the failure pattern. Various surface properties may therefore be indicated for different anatomical and host conditions. Finally, th e histopathology of implant losses is described and discussed in relat ion to the clinical findings.