Experimental Study of Retentive Force with Implant Abutment

Abstract

In order to investigate how much the retentive force of an implant overdenture is affected by the position of the measuring force, or the type, number, setting position of the attachment, the retentive force of an implant overdenture using three kinds of attachments, i.e., clip, ball and magnet, respectively, was measured experimentally, and results were analyzed and summarized as follows.
1. In the case in which the three attachments were employed, the retentative force at the midline of the central anterior teeth and at the first molar teeth was 34.95±1.39 N and 4.18±0.34 N, respectively for the clip, 63.92±2.44 N and 12.53±0.64 N, respectively for the ball, 3.96±0.93 N and 0.84±0.25 N, respectively for the magnet. For all points measured, the value of the retentive force for the ball attachment was greatest, followed by the clip attachment, and was least for the magnet attachment (p＜0.001). In the case of the magnet, the retentive force of the implant overdenture was extremely weak compared with the clip and ball attachments.
2. In the case of two ball-attachments embedded at both edges of the dental arch form, the retentive force at the midline of the central anterior teeth and at the first molar teeth was 32.58±0.51 N and 14.23±0.36 N, respectively, and in the case of one ball-attachment embedded at the midline of the central anterior teeth of the dental arch form, the force was 25.19±2.19 N and 10.56±0.57 N, respectively. Consequently, the retentive force of both the two or one ball-attachment employed was found to be clinically sufficient to secure the implant overdenture.
3. The retentive force was affected by not only the position of the measuring force but also by the type, number, and setting position of the attachments.