Objectives: The aim of this study was to compare the retention values of two stud attachments with two different designs in Mandibular implant overdenture.
Materials & methods: Eight completely edentulous patients were selected to receive mandibular complete overdentures supported by 4 implants. At the prosthetic phase the patients were divided into two groups; Group I: 4 Patients of this group received a mandibular overdenture retained by a ball abutment and a nylon matrix, Group II: 4 Patients of this group received a mandibular overdenture retained by OLS attachment with a PEEK matrix. Retention values were measured in vitro using universal testing machine at the time of installation, 6 and 12 months.
Results: The results of this study demonstrated no significant difference between the conventional ball with nylon cap and the PEEK attachment at the installation time, while analysis of the retentive values after 6 and 12 months showed a significant decrease in retention values of the ball and socket attachment with nylon matrix, while the OLS attachment with PEEK matrix showed higher retentive means compared to the ball.
Conclusion: Within the limitation of this study it was concluded that PEEK OLS attachment attains better values of retention with time when compared to conventional ball and socket attachments with nylon matrix.