Effects of attachment type on the mobility of implant-stabilized oveudentures - An in vitro study

Purpose: To stabilize overdentures, a wide range of attachments to implants is suggested. Although there is evidence that denture stability is an impo rtant factor for patient satisfaction, there are no data on how these attac hments may reduce denture mobility. It was the purpose of this study to com pare the effects of different types of attachments on the mobility of impla nt-stabilized overdentures in vitro, designing a measurement device that co uld also be used in vivo. Materials and Methods: On an acrylic model with 2 implants in the canine areas, magnets were fixed to one of the implant abu tments. Four Hall-effect devices were attached to the denture opposite the magnet, which allowed contact-free measurements of denture movements. Resul ts: In vitro experiments loading an overdenture showed very small, largely insignificant differences in denture mobility when different bar or ball at tachments were used. Geometric aspects of load application were more import ant than the choice of attachment. Conclusion: The measurements gave no gui de to the choice of an attachment. The similarity of the attachments must b e confirmed by in vivo measurements.