Prosthetic Aspects and Patient Satisfaction with Two-Implant-Retained Mandibular Overdentures: A 10-Year Randomized Clinical Study

Purpose: This study aimed to compare the prosthetic aspects and patient satisfaction with prosthetic care in two-implant-retained mandibular overdentures, whether implants were splinted with a bar or left with magnets or ball attachments. Materials and Methods: Thirty-six completely edentulous patients had two Brånemark implants placed in the mandibular canine area. A randomized procedure allocated patients into three groups of equal size, each with a different attachment system: bars, magnets, or balls. Prosthesis retention and mechanical as well as soft tissue complications were recorded in addition to patient satisfaction. A linear mixed model was fitted with attachment type and time as classification variables and adjusted by Turkey's multiple range test. Results: Ball-retained overdentures showed at year 10 the greatest vertical retention force (1,327 g), followed by bars (1,067 g) and magnets (219 g). In the ball group, need for tightening of abutment screws was the most common mechanical complication; in the magnet and bar groups, respectively, the most common complications were wear and corrosion, and the need for clip activation. Prosthesis stability and chewing comfort for the overdenture were rated significantly lower for the magnet group compared to the ball and bar groups. Prosthesis stability of the maxillary denture was rated significantly lower in the bar group compared to ball and magnet groups. Conclusion: The ball group scored best in relation to retention of the overdenture, soft tissue complications, and patient satisfaction at year 10. The bar group scored lower for comfort and stability of the maxillary denture. Magnets offered patients the least comfort.