Mandibular Implant-Supported Overdenture: An In Vitro Comparison of Ball, Bar, and Magnetic Attachments
In an implant-supported overdenture, the optimal stress distribution on the implants and least denture displacement is desirable. This study compares the load transfer characteristics to the implant and the movement of overdenture among 3 different types of attachments (ball-ring, bar-clip, and magnetic). Stress on the implant surface was measured using the strain-gauge technique and denture displacement by dial gauge. The ball/O-ring produces the optimal stress on the implant body and promotes denture stability.

Figure 1 . Strain gauge arrangement. Figure 2. Channels and loading point. Figure 3. Wheatstone bridge configuration. Figure 4. Denture displacement directions.

Figure 5 . Strain in the implant during load application in the ball and ring attachment. Figure 6. Strain in the implant during load application in the magnetic attachment. Figure 7. Strain in the implant during load application in the bar and clip attachment. Figure 8. Denture displacement noted across different attachments.
Contributor Notes