Overdenture as a treatment modality for both partially and fully edentulous patients is costeffective and less expensive.The purpose of the present study was to examine the newly fabricated attachments by comparing them with conventional O-ring attachment in vitro in terms of retention force and cyclic aging resistance.A total of 150 samples were prepared and divided into five groups according to the materials used (O-ring attachment,Deflex M10 XR,Deflex Classic SR,Deflex Acrilato FD,and flexible acrylic resin).The retention force of different attachments was measured by a mini dental implant after three subsequent aging (0,63,and 126) cycles in the circumstances similar to the oral environment.The gap space between the head of the implant and the inner surface of the attachments was detected.Two-way analysis of variance (ANOVA) analysis with multiple comparisons test was applied for statistical analysis.The results showed that Deflex M10 XR had the highest retention force and the lowest gap space after cyclic aging;in addition,by comparing the relative force reduction,the lowest values were obtained in the O-ring attachment and the highest values in the flexible acrylic resin attachment.The retention force measured after cyclic aging for the Deflex M10 XR attachment was greatly improved when compared with the O-ring attachment and other types of attachment materials;in addition,the Deflex M10 XR attachment exhibited the minimum gap space between the inner surface and the mini dental implant head.In conclusion,Deflex M10 XR has the ability to withstand weathering conditions and retains its durable and retentive properties after aging when compared with other attachments.