Retentive characteristics of a vinylpolysiloxane overdenture attachment system.

Abstract

Numerous different attachments are used to retain overdentures on implants. The purpose of this study was to evaluate a new chairside attachment system based on polyvinylsiloxane (PVS). A total of 250 specimens were fabricated (n = 10) to measure the retention force (RF) in dependence of the following parameters: fatigue (after 100, 200, 500, 1,000, and 5,000cycles of dislodging), thermal undulation (10,000cycles between 5 and 55°C), implant angulation (0°, 5°, and 10°), and disinfection (three different agents). Three different PVS materials (shore hardness (SH), SH25, SH50, and SH65) were evaluated; locator attachments (LR blue) served as controls. Data were imported into a statistical program and analyzed at a 5% level of significance. Initial RFs were dependent on the shore hardness (p ≤ 0.001, ANOVA). No changes in RFs were observed for PVS groups after repeated dislodging and thermal undulation. Locator attachments revealed a significant decrease in retention force of up to 58% (p ≤ 0.001, Fig.3). No significant changes in RFs were induced by implant angulation. Retention force was decreased in some PVS groups after storage in disinfection solution. Polyvinylsiloxane attachments provide an alternative to locator attachments, exhibiting better stability of the retention force. The presented directly fabricated chairside attachment system represents RFs superior to existing attachment systems after artificial aging.