Aim: We investigated attenuation of the retention force on the female end (silicone soft relining material) with repeated mounting/ removal and determined the allowable angle between the male ends for mounting/removal. Materials and methods: Attachments consisting of metal ball anchors (diameter 2.5, 2.7, or 3.0 mm) for the male end and a silicone soft relining material for the female end were subjected to retention force measurement and allowable angle tests. The frequency of mounting/removal in 1 year was estimated assuming mounting/removal four times a day. The allowable angle test used two pairs of male ends with the between-male angle set at 0, 15, 30, or 45°, and the angle between the male ends joined with the female end was measured. The retention force at the initiation of the experiment and at each time-point was compared using one-way analysis of variance (ANOVA) followed by Dunnett's test (á = 0.05). Results: The retention forces of the male ends with a diameter of 2.5, 2.7, or 3.0 mm at the initiation of the experiment were 3.8 ± 0.3, 5.2 ± 0.2, and 5.5 ± 0.2 N respectively. After repeated mounting and removal corresponding to use for 1 year, a significant decrease in retention force was noted in all male ends (3.3 ± 0.1, 3.8 ± 0.2, and 4.3 ± 0.1 N respectively). It was also found that mounting/removal was possible up to a betweenmale- end angle of 45°. Conclusion: Under the conditions of this experiment, the retention force decreased with repeated mounting and removal of the female end prepared with silicone soft relining material. Additionally, a large between-male angle for mounting/removal was allowable, and mounting/removal was possible up to 45°. Clinical significance: This system may save time and expense and could be used to treat patients easily in their home or a nursing home.