2,3-Branching benzyl ether dendrimers for the enhancement of dental composites

The globular and highly branching nature of the 2,3-dihydroxybenzyl motif was utilized in the development of novel dental composite additives. Dental composites were formulated with varying percentages of multi-methacrylated dendritic additives and evaluated for the corresponding influence on material properties. The flexural strength of composites containing only 0.5% of multi-methacrylate dendritic additive improved 21-35%, compared with control. Addition of higher molecular weight (Mw) dendrimers resulted in composites with greater flexural strength. Higher concentrations of additive afforded no additional benefit to the composite strength. The degree of polymerization as a function of increasing additive Mw or concentration indicates a strong dependency on the diffusion coefficient of the dendrimer. Low concentrations of dendritic additive effected up to an 85% decrease in acetone-extractable material from the cured composite matrix. These studies demonstrate the ability of highly globular, highly cross-linking additives to improve composite properties even at very low concentrations.