Simulated Wear Resistance of Ball and Socket Over denture Attachments

The widespread use of implant supported ball and socket over denture attachments necessitates the evaluation of their retentive profiles especially after wear. Objectives: To determine the resistance of over denture attachments after 18 months of simulated wear. Methods:Twelve attachments (Nobel Biocare) were tested at baseline and after repeated simulated wear.The ball and socket attachments were subjected to repeated engagements and disengagements on a wear inducing machine. Artificial saliva was applied to the ball attachments after every 50 cycles of wear. The attachments were tested for retention after 550, 1100, and 1650 cycles,which respectively represents 6, 12 and 18 months of patient wear.After every wear period the retentive force of each component was measured using an Instron machine.Results:The ANOVA signed rank test analysis indicates that there is no significant(p<0.05)change from baseline(23.07N) and after 18 months of simulated wear(21.65N). Conclusion:The over denture ball and socket attachments tested in this study provide sufficient retention and therefore do not require replacement within a wear period of 18 months.