Tertiary aromatic amines were synthesized with various nitrogen and ring substituents. They were compared with commercial homologues using composites based on dimethacrylate monomer formulations containing benzoyl peroxide. Equiinolar amounts of the different amines were the only variables. Although accelerating ability was a function of both ring and nitrogen substitution, color stability was influenced more by the substituents on the ring than by the substituents on the nitrogen.Previous reports have shown that a relationship exists between the structure of an aromatic tertiary amine and the color stability of the methacrylate polymer containing the amine.12 The color stability decreases in the order shown in the illustration. The hardened specimens containing NNdimethyl-sym-m-xylidine (DMSX) [also referred to as DMDA (NN-dimethyl-3,5-dimethylaniline) previously3] had the lightest color and were the most color stable.The purpose of this investigation was to prepare and evaluate aromatic amines of similar general structure, but with greater molecular weights than accelerators now in use. Increased molecular size might reduce solubility in tissue fluids and thus lessen ease of diffusion into the pulp or other tissues.4 Use of amines with such properties should lower toxicities and produce less pulpal irritations in comparison with the

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SynopsisThe rate of polymerization of a methacrylate monomer was influenced by the molar ratio of benzoyl peroxide to an aromatic tertiary amine accelerator when the product of the concentrations of these was kept constant. The maximum rate, measured as the minimum gel time, occurred in monomer solutions containing about 1.5 moles of peroxide per mole of amine.