Implant-Retained Overdentures Using an Attachment with True-Alignment Correction: A Case Series

Implant parallelism is considered a cardinal criterion for the successful rehabilitation of edentulous jaws with implant-retained overdentures (IODs), especially if freestanding anchorage systems (unsplinted attachments) are employed. This report aimed to demonstrate the successful use of a novel IOD attachment with a true-alignment capability in complex cases with large inter-implant angular discrepancies. The report further aimed to highlight the use of a novel polyetherketoneketone (PEKK) framework as a reinforcement material for fabricating a completely metal-free IOD. Although some freestanding attachments exploit their geometric form and/or use various retentive inserts to compensate for inter-implant angular discrepancies, a true-alignment correction is seldom achieved. The CM LOC FLEX (Cendres+Métaux attachment provides a true alignment correction and produces parallelism between implants in clinical situations where the implants are not parallel to one another. The functionality of the CM LOC FLEX was described in this case report for two different clinical situations: a conventional mandibular IOD retained by two implants, and a maxillary IOD retained by four implants. Both cases involved a complex clinical situation with compromised implant parallelism. The CM LOC FLEX abutment has a true-alignment correction mechanism that can be advantageous in clinical situations where the inter-implant axial alignments are not parallel. PEKK frameworks are lightweight, strong, and can be esthetic substitutes for conventional metal frameworks. However, welldesigned clinical studies are further needed to assess the clinical performance as well as the maintenance requirements of the illustrated novel attachment and the PEKK framework before advocating them as validated and standard protocols.