Objectives: 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).
Material and methods: 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 5,000 cycles of dislodging), thermal undulation (10,000 cycles 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.
Results: 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.
Conclusions: Polyvinylsiloxane attachments provide an alternative to locator attachments, exhibiting better stability of the retention force.
Clinical relevance: The presented directly fabricated chairside attachment system represents RFs superior to existing attachment systems after artificial aging.