ABSTRACT Statement of the problem: Insufficient long-term retrospective data is evaluating marginal bone loss and retention of four-implant Locator-retained mandibular overdentures.
Purpose: To assess marginal bone loss and retention of four-implant Locator-retained mandibular overdentures over seven years at the time of overdenture insertion (T0), 1 year (T1), and 7 years (T7) after insertion.
Material and methods: This retrospective study included 27 completely edentulous patients with maxillary single denture, and four parallel implants were placed interforaminal, and they already have a mandibular four-implant retained overdenture with LOCATOR attachments.