Abstract: Objective To evaluate the clinical outcomes and prosthetic complications of mandibular twoimplant overdentures retained with ball attachments over 3 years.Methods 10 patients with severely reabsorbed mandibular edentulous jaws were treated with delayloaded mandibular twoimplant overdentures retained with ball attachments 3 months after the implants were placed in the mandibular anterior region with good consistency in the horizontal level,angulation,and distance from the midline.The implant survival rate,periimplant tissue status,prosthetic complications and patients′ satisfaction were evaluated 1 week,1 year,2 years and 3 years after overdenture rehabilitation.Results Over 3 years′ rehabilitation of mandibular twoimplant overdentures retained with ball attachments,no implants failed,the overall marginal bone loss was lower than 1mm,the mucosal conditions were healthy,and the patients′ satisfaction was significantly improved and remained high over time.The most common prosthetic complications were replacement or reactivation of an attachment matrix,and the frequency of prosthetic maintenance per patient per year was 0.67 during the 3year observation period.Conclusions Mandibular twoimplant overdentures retained with ball attachments are a viable treatment modality with good longterm clinical outcomes,on condition that the placement of implants is well designed.

Key words: edentulous mandible, mandibular overdenture, dental implantation, ball attachment, follow-up study