【正文】 wing SecondStage SurgeryFailure to IntegrateMobility of an exposed implant is indicative of failure of the implant to integrate. The implant and many associated soft tissue should be removed. Failure to IntegrateImmediate placement of a larger diameter implant may be considered. It may be prudent, however, to leave the site to heal, with time to replan treatment. Excessive Bone over the Cover Screw Bone Growth between the Cover Screw and Implant If the cover screw has not been placed directly onto the implant head at the time of firststage surgery, bone may grow into any gap left between implant head and cover screws. Bone Growth between the Cover Screw and ImplantProsthetic ComplicationsProsthetic ComplicationsBiomechanical Problemsthey may include:●fracturing of the prosthesis● loosening or fracturing of abutment screws Biomechanical ProblemsFracture of the prosthesisFracture of the prosthesis Partial loss of acrylic or porcelain and fracture of the metal framework is more often than not the result of excessive loading or poor design of the framework. Fracture of the prosthesisLong cantilevers can lead to both fracture of the prosthesis and screwloosening. As with fracture of any restoration, the cause of the failure must be diagnosed before planning remedial treatment. Loosening or Fracturing of ScrewsOverload, poor fit of framework or ponents and excess or inadequate tightening are all reasons for the loosening or fracturing of screws. Prescribed protocols must be followed to retrieve and replace fractured screws successfully.Lute Failure in a CementRetained ProsthesisExcessive loading and poor fit of the superstructure are the most mon causes for this type of failure. Lute Failure in a CementRetained Prosthesis Remedial treatment may include repositioning the superstructure to improve fit. Repeated cement failure may necessitate a remake of the prosthesis.Fracture or Loss of the ImplantBone loss may continue to a level at which inherent weaknesses in the implant result in fracture. Excessive loading may result in loss of integration.Fracture or Loss of the ImplantFurther treatment under such circumstances is highly dependent on the particulars of the case. Removal of a fractured implant may be problematical. Physiological ProblemsPhysiological problems may include: softtissue inflammation periimplant mucositis and periimplantitis bone loss resulting in implant thread exposure depending on severity Physiological Problemsbone loss may necessitate implant replacement loss of integration – implant removal and perhaps replacement.MaintenanceThe importance of a carefully planned, fully adheredto maintenance programme cannot be overemphasized in the longterm management of implantretained prosthesesMaintenance In the assessment and treatmentplanning of implant cases, it is essential that patients take responsibility for the longterm care of their prostheses. MaintenanceA degree of dexterity will be needed for the patient to clean the prosthesis adequately, and this must be carefully assessed at the treatmentplanning stage. MaintenanceFailure or the inability of patients to maintain and look after their implantretained prosthesis may lead to many varied problems, including failure in clinical service.MaintenanceIt is essential that baseline radiographs are taken at pletion of treatment. Progressive bone loss may be related to excessive loading. MaintenanceMost implant systems show a small amount of bone loss in the first year after loading, but should remain stable thereafter. Maintenance It is therefore remended that all patients be seen three months after the pletion of treatment, when careful clinical examination is indicated. This should include:● assessment of the prosthesis● examination of the soft tissues● radiographic examination to assess bone height.The Prosthesis Clinical examination of the prosthesis should – in addition to checking fit, stability, occlusal relationship and patient acceptability – focus on the sufficiency of the patient’s oral hygiene. Th