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An easy and efficient route to synthesize gel materials based on polymeric ionic liquids (PILs) is presented. The radical polymerization of imidazolium (Im)‐based ionic liquids (ILs) bearing a vinyl group ([VEIm][Br], [VEIm][Ac], [VBIm][Br], [VBIm][Cl]) with crosslinker (CL) N,N′‐methylenebisacrylamide (Bis) in water results in polyionic liquid hydrogels. Thermal and mechanical properties (tensile and compression tests) are investigated and compared with two different types of hydrogels. One is a polyacrylamide (PAAm) hydrogel having covalent‐type crosslinking. The other is an alginate‐based hydrogel having ionic‐type crosslinking. Prepared IL‐hydrogel materials provide favorable flexibility, adjustable by varying the CL ratio and water content. The higher the CL ratio is, the higher the fragility of the gel matrix. The gelation time of the hydrogels depends on the alkyl chain length, as well as the size of the anion.

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Determination of mechanical properties of nano‐hybrid dental composites leads to strong correlation to material's ultrastructure. Not only does total filler content in percentage of weight affect the mechanical properties, but the combination of optimal filler size and shape with homogeneous distribution of filler particles and an optimal amount of different sized fillers in finally cured dental composites lead to desired mechanical and thermo‐mechanical properties.

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Aesthetical and biomechanical requirements on fiber-reinforced endodontic posts play an important role in clinical application. Leading to a long-term clinical success, post systems must ensure an adequate force transmission and optimal retention behavior into the root channel. The aim of this study was to determine the microstructure and morphology of commonly used fiber reinforced endodontic posts in vitro. Post-specific fiber diameter, fiber arrangement over the cross-sections and length, and fiber-matrix ratio could be associated with mechanical properties, such as three-point bending strength and structure modulus. Furthermore, our investigation focused on the quantification of the wettability of the post surface. By using a modified contact-angle measurement, the meniscus on the post surface was characterized. In additional investigations, posts were inserted in artificial root channels and the extraction force was measured. The results show a strong correlation between the extraction force and the wettability of the post surface.

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