2.3. Preparation of Experimental Resin Formulations

Urethane methacrylate monomer and PEG-containing oligomers were mixed together with Bis-GMA, TEGDMA, DMAEM, and CQ according to the composition presented in Table 1, in a dark room. All six systems were well-mixed at room temperature to obtain a homogeneous, colourless liquid mixture and were stored in the dark before use.

Chemical composition of prepared experimental resin.

Dental resins were cured by the principle of photo polymerization, due to the photo-initiation system, which comprises a photo-initiator (CQ) and a tertiary amine (DMAEM). We used an LED-curing light Woodpecker (Guilin Woodpecker Medical Instrument CO. Guilin, China) with a constant intensity of 1000 mW/cm².