Mandibular Overdentures Retained by Two Implants:10-Year Results from a Crossover Clinical Trial Comparing Ball-Socket and Bar-Clip Attachments

Purpose: The aim of this study was to evaluate patient satisfaction and clinical and prosthetic outcomes of two-implant mandibular overdenture treatment with different attachment types after 10 years of function. Materials and Methods: In a crossover clinical trial, 18 edentulous subjects with complaints regarding their mandibular dentures received two implants and a new denture with magnet, ball-socket, or bar-clip attachments that were applied in a random order. At the end of the experiment, the attachment type of their choosing was fitted in the overdenture. After 10 years, 7 subjects with a ball-socket and 7 subjects with a bar-clip attachment were available for evaluation. The same questionnaire from 10 years before was completed, and subjects were asked to express their overall appreciation of their dentures on a visual analog scale (VAS). Six scales of denture complaints were constructed. Mean scale and VAS scores between initial evaluation and after 10 years were compared. In addition, marginal probing depths, Bleeding Index, and radiographic marginal bone loss were assessed. Results: There was no marked difference in satisfaction between subjects with ball-socket-and bar-clip-retained two-implant mandibular overdentures at initial evaluation and after 10 years of function. Conclusion: Patients' appreciation of their implant-retained denture was and remained high over time. Clinical parameters revealed healthy mucosal conditions and stable marginal bone levels, determined radiographically. Probing depths around implants provided with ball-socket attachments were slightly shallower than those with bar-clip attachments after 10 years of function (P <.05). Int J Prosthodont 2010;23:310-317.