Mandibular Overdentures Retained by Four Locator Attachments Versus Four-Implant Bar Attachments

This 10-year retrospective study investigates residual ridge changes in edentulous patients treated with mandibular overdentures (ODs) retained by either four Locator attachments or a four-implant bar system. Although two-implant ODs are well established, four-implant configurations may offer enhanced stability and function. Locator and bar attachments are commonly used, but their long-term effects on bone resorption patterns-especially posterior mandibular and anterior maxillary resorption-remain unclear. By standardizing implant positions, this study aims to directly compare the two systems to help guide clinicians in selecting the most effective attachment type for long-term success.