INTERFACE WIDENING Localized by Gruen zones. INTERFACE WIDENING Assessment of width Radiolucent zones wider than 2 mm are evidence for loosening. Radiolucent zones less than 1 mm are acceptable. Radiolucent zones less than 2 mm that are stable and not progressive after 6-12 months and. 13 The consequential offset loads at the interface are of sufficient magnitude to overcome the clamping forces of the screw, as a result, screw gets stretched, broken or loosened. To overcome this, various biomechanical considerations such as preload to be 75 of the yield strength. Principles of screw - retained and cement - retained fixed implant prosthesis: A critical review. J Interdiscip Dentistry serial online 20 May 16;. Available from: p?/147329 Long-term success is the prime goal for any restoration in prosthetic treatment and so is it with implant dentistry. However, longevity of the restoration, both functionally as well as esthetically depends on various factors prevailing in the clinical situation. One such factor of immense importance is the selection of connection between the implant abutment and the final prosthesis. No comparison radiographs were available. Current radiographs demonstrates markedly tilted cup which has migrated laterally from pelvis. 12/93 8/98 MIGRATION FEMORAL COMPONENT SUBSIDENCE Sinking of component over time Femoral component Stem sinks into femur Trochanter position too proximal Acetabular component Cup sinks into pelvis and.
This sign appears slowly, requiring comparison with baseline or the oldest studies available. Obviously abnormal component positioning without comparison studies is adequate for diagnosis of loosening 10/01 11/01 COMPONENT MIGRATION ACETABULAR CUP ACETABULAR COMPONENT Progressive protrusio and tilt 2/00 1/01 ACETABULAR COMPONENT Migrating acetabular cup.