Synthesis and Characterization of Microcapsules as Fillers for Self-Healing Dental Composites

This article proposes the synthesis and characterization of (triethylene glycol dimethacrylate-N,N-dihydroxyethyl-p-toluidine) TEGDMA-DHEPT self-healing microcapsules for their inclusion in dental composite formulations. The obtaining method is the in situ emulsion polymerization of the (poly urea-formaldehyde) (PUF) coatings. The microcapsules were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), high-performance liquid chromatography (HPLC), and low-field nuclear magnetic resonance (NMR) techniques. The optimal formation of uniform microcapsules is achieved at a stirring speed of 800 rpm and centrifugation is no longer necessary. HPLC demonstrates that the microcapsules formed at 800 rpm show a better control of liquid release than the heterogeneous ones obtained at a lower stirring speed. The centrifuged samples have rounded shapes, with dimensions between 80 and 800 nm, while the non-centrifuged samples are more uniform, with a spherical shape and dimensions of approximately 800 nm.