Synthesis and characterization of dimethacrylates containing quaternary ammonium functionalities for dental applications

Abstract

Objectives The widespread incidence of recurrent caries highlights the need for improved dental restorative materials. The objective of this study was to synthesize low viscosity ionic dimethacrylate monomers (IDMAs) that contain quaternary ammoniums groups (antimicrobial functionalities) and are compatible with existing dental dimethacrylate-based monomers. Such monomers have the potential to copolymerize with other methacrylate monomers and produce antibacterial polymers. Methods Two monomers (IDMA-1 and IDMA-2) were synthesized using the Menschutkin reaction and incorporated at 0% to 30% (by mass) into a 1:1 (by mass) bisphenol A glycerolate dimethacrylate (BisGMA):triethylene glycol dimethacrylate (TEGDMA) resin. Resin viscosity was quantified using rheology, and polymer degree of conversion (DC) and surface charge density were measured using Fourier transform infrared spectroscopy (FTIR) and fluorescein binding, respectively. Effects of IDMA-1 on initial attachment of Streptococcus mutans and on viability and enzymatic activity (formazan reduction) of RAW 264.7 macrophage-like cells were quantified. Results IDMA-1 and IDMA-2 were prepared and characterized. IDMA-1 was miscible with BisGMA:TEGDMA and slightly increased the resin viscosity and DC. As expected, polymeric surface charge density increased with increasing IDMA-1. Incorporation of 10% IDMA-1 into BisGMA:TEGDMA reduced bacterial colonization without affecting viability or enzymatic activity of mammalian cells. Increasing IDMA-1 up to 30% had no additional effect on bacterial coverage, but ≥ 20% IDMA-1 significantly reduced macrophage density, viability, and enzymatic activity. Leachables from polymers containing IDMA-1 were not cytotoxic. Significance The Menschutkin reaction provides a facile, convenient means to synthesize new monomers with quaternary ammonium groups for dental and medical applications.

Influence of addition of [2-(methacryloyloxy)ethyl]trimethylammonium chloride to an experimental adhesive

“…Although there is a statistically significant difference in the degree of conversion, its values corroborate those of the literature, 4 but it is not possible to state they will be clinically significant. METAC is a monomethacrylate 16 and there may have been fewer unreacted double bonds after the reaction, not indicating reduced polymerization, though. The degree of conversion is directly associated with the mechanical properties of polymers; however, it is not necessarily related to crosslink density.…”

“…15 Thus, the molecular structure of [2-(methacryloyloxy) ethyl]trimethylammoniumchloride (METAC) (Figure 1), which contains a quaternary ammonium group (antimicrobial functionalities), allows copolymerization with other methacrylate monomers and produces antibacterial polymers. 16 Therefore, METAC-containing materials could be incorporated into adhesive systems to inhibit bacterial activity, leading to long-term efficacy. 17 Considering the short alkyl chain length of METAC, antimicrobial activity probably derives from the charged nitrogen atom of quaternary ammonium, which concentrates the positive charge.…”

Quaternary ammonium compounds in dental restorative materials

“…These monomers had two aliphatic C=C in their molecular structures, and it was likely that more antimicrobial monomers could be incorporated into resin matrix when polymerized with resin matrix, and antimicrobial activities of materials incorporating these monomers would be greatly improved. Antonucci 11) and Cheng et al 12) have successfully synthesized two crosslinking antimicrobial monomers with two polymerizable groups by Menschutkin reaction 13) , and their polymerization performance were also greatly improved.…”

A resin composite material containing an eugenol derivative for intracanal post cementation and core build-up restoration

“…Several low viscosity ionic mono and dimethacrylate monomers containing quaternary ammoniums groups such as 1,2-Methacryloyloxydodecylpridinium bromide (MDPB) and bis (2-methacryloyloxyethyl) dimethylammonium bromide (IDMA) imparting antimicrobial properties in conjunction with existing dental dimethacrylate-based monomers have been reported [16,17]. However, adverse effects on mechanical properties associated with high monomethacrylate content were found.…”

“…However, adverse effects on mechanical properties associated with high monomethacrylate content were found. In addition, some of the quaternary ammonium based monomers exhibit miscibility problems with hydrophobic dimethacrylates [17].…”