The Preparation of Experimental Resin-Based Dental Composites Using Different Mixing Methods for the Filler and Matrix

Resin-based composites are common and widely used materials in dentistry in direct and indirect applications. Their mechanical properties depend on the composition and homogeneity of the resulting structure. This study aims to optimize the mixing process to obtain the most homogeneous mixture possible, which will allow for the better mechanical properties of the composite. A mixture of bis-GMA/UDMA/HEMA/TEGDMA monomers forming a polymer matrix was filled with silanized silica (45 wt%) using different mixing methods. This study analyzed five manufacturing methods—hand mixing (agate mortar), mixing in a centrifugal Hauschild SpeedMixer, and the hybrid method—combined with the abovementioned methods. The effect of the mixing method on the Vickers hardness (HV), flexural strength (FS), compressive strength (CS), and diametral tensile strength (DTS) of the produced composites was investigated, and the stresses generated during composite polymerization were determined. Mechanically prepared composites have the highest flexural strength and hardness. The lowest shrinkage stress was achieved by the composite, which was prepared partially manually. The results showed that the mixing method affects the morphology of the filler and, hence, the strength properties of the resulting material.