This review article describes studies involving synthesis and characterization of novel matrix monomers, particularly dimethacrylate monomers designed mainly for the preparation and evaluation of dental composite materials. The work is based upon the hypothesis that the problems with current matrix materials are largely due to the quality of diluent monomers required to control matrix viscosity and therefore that the use of matrix monomers of lower viscosity would lead to improved properties. The recent work in our laboratory confirmed this hypothesis. Modifications of the traditional BIS-GMA monomer were made together with the monomers in which the control - C(CH₃)₂ - is replaced by groups containing phosphorus or fluorine. In each series, three monomers were prepared, one with the pendant -OH group characteristic of BIS-GMA, and the others with the-OH replaced by -H and -CH₃. Synthetic schemes and conditions were adjusted to avoid hydrogen bonding (responsible for high viscosity) and oligomerization, thus minimizing viscosity. In a limited number of examples where the viscosity of the pure monomer exceeded the viscosity characteristic of present uncured matrix materials, it was diluted with TEGDMA as needed to produce a standard viscosity. All the monomers were evaluated for viscosity, wetting ability, water sorption and curing shrinkage. Their corresponding polymers were tested for water sorption and wetting ability by water. It has been concluded that with reference to water sorption of BIS-GMA and TEGDMA copolymer networks, significant increase in water uptake with increases in TEGDMA may be attributed to the nature of the crosslinking which results in less efficient macromolecular packing and hence increased accommodation of water in microvoids. However, this hypothesis was tested by monitoring changes in density and judged to be inadequate. Thus, the influence of crosslinking in increasing water uptake remains unexplained. The most striking and interesting findings in our recent work were that the newly synthesized monomers with pendant methyl groups in the side chains with Bis-A and 6F cores importantly did not require any dilution to achieve good working viscosities. More strikingly and consistent with our hypothesis that suppression of internal hydrogen bonding induced by -OH of BIS-GMA will reduce the viscosity, and that the viscosity was significantly reduced from 1200 Pa s to 2.7 Pa s by the replacement of -OH group in BIS-GMA with silyl groups. With the increase of initiator concentration and reaction temperature, it was seen that higher conversions were obtained. It has been concluded that the proper design of the molecular structure by lowering the viscosity and the glass transition temperature of the monomer significantly augments the rate of conversion under typical free radical polymerization conditions.