ABSTRACT The global market size for restorative dentistry is estimated to be around $20.2 billion in 2023 and expected to grow to $36.2 billion by 2030. In the US, $2.8 billion is spent on restorative materials annually, predicted to increase to $5.2 billion by 2030. To address such a demand, the most widely used direct placement dental restorative materials are bisphenol A-glycidyl (meth)acrylate (Bis-GMA) resin-based composites. However, the BPA leaching from Bis-GMA can lead to health issues like male reproductive abnormalities, heart disease, and diabetes. In addition, these resins require utilization of reactive diluting agents to decrease their viscosity, which leads to a significant curing shrinkage and stress, reducing longevity of the restorations. Thus, there is a strong need to develop BPA-free alternatives with better performance than the currently used options. While significant efforts have been made to develop BPA-free dental resins utilizing urethane (meth)acrylate monomers, none of the proposed alternatives can significantly surpass the properties of the currently used urethane di(meth)acrylate (UDMA). To close this gap, the PI recently invented novel urethane-based monomers, which if mixed with acidic comonomers, reach virtually complete degrees of conversion (>98%) under ambient photocuring, and exhibit mechanical properties 2 to 3 times better than that of the UDMA- or BisGMA-based resins. In addition to superior modulus and strength, these resins possess notably better toughness and strain tolerance as well as low polymerization shrinkage and stress. Such an excellent combination of properties makes them a very promising alternative to Bis-GMA as the basis for dental composites. In Phase I, the collaborating institutions, Callentis Consulting Group, University of Colorado, and New Mexico State University will determine feasibility of the novel resins as high-performance BPA-free functional dental composites. Aims: 1: Narrow down the list of preselected commercially viable composite constituents, both resin and filler components, and prepare the corresponding samples for further tests. 2: Perform numerical modeling of the mechanical behavior of the selected resins and their composites to determine optimal microstructures leading to the best performance, as well as uncover any reinforcement-related issues. 3: Carry out experimental characterization of uncured resins and their composites. 4: Evaluate feasibility of the proposed material by measuring properties of cured neat resins and their optimal composites, assessing any microstructural defects, cytotoxicity and testing remineralization potential of the resins filled with hydroxyapatite particles. At the end of Phase I, the team will establish feasibility and commercial viability of the proposed materials, as well as outline the optimal filler parameters to maximize the performance of the proposed composites. Phase II will focus on comprehensive testing and refinement of the...