Methods: Each 5 identically prepared dentures out of PMMA (Paladon®65, Palapress® vario) and Eclipse™ with different denture teeth (Genios®P, Dentsply De Trey; Vitapan® 3D-Masters, Vita Zahnfabrik; and Trubyte®, Dentsply De Trey) were exposed to 5000 thermal changes (5º-55º-5º per minute), stored in 5% methylenblue dilution (1h at 37°C), and then they were put into a cabinet desiccator for 2 h to analyse colour penetration into the denture-teeth compound. Afterwards the dentures were exposed to an axial force acting on the incisal region of the denture teeth (30000 strokes of 50 Newton for 0.6s). Subsequently the dentures had to pass the colour penetration experiment again. The final experiment was a shear test to stress denture teeth up to their fracture operated by a standard apparatus (Zwick).
Results: The penetration test showed that all resin denture teeth had a perfect chemical bonding, and the ceramic teeth had an undisturbed mechanical bonding to their bases. The mechanical stress to 30000 strokes was negligible. There was no significant difference of the retention strength between ceramic teeth and the three different denture base products, whereby the compound between ceramic teeth and Eclipse™ revealed best results at a median of 406 N. The retention force between synthetic teeth and Eclipse™ showed minimum values with a median of 300 N.
Conclusions: Whereas conventional PMMA denture material yielded a superior bonding to acrylic teeth, the new material Eclipse™ showed sufficient and similar bonding to both acrylic and ceramic teeth.