Introduction

The present invention is a new series of amphipathic antibacterial monomers based on quaternary ammonium salts (QAMs), which can be used in both primer mixtures (hydrophilic) and bonding resins (hydrophobic) for dental use, to prevent the development of secondary caries at the margins of tooth restoration.

Technical features

The eight newly synthesized structures showed bactericidal activity even at low concentrations on both Gram-positive and Gram-negative bacteria, while maintaining extremely limited cytotoxicity on human dental pulp cells.

These new monomers, when copolymerized in methacrylate resins, exhibited good activity by providing a polymeric material with bactericidal effect by contact. This represents an improvement when compared to most of the dental structures described in literature, which often show only a bacteriostatic effect after polymerization.

Several previously synthesized QAMs structures have been conceived for use either in bonding or primer resin systems. On the contrary, the newly prepared monomers have a much wider versatility of use, having showed excellent compatibility with different methacrylate monomers (hydrophobic, hydrophilic and acidic) allowing the formulation of antibacterial resins capable of achieving satisfactory degree of conversion through photopolymerization and showing unchanged mechanical properties.

Possible Applications

• Preparation and marketing of resin mixtures for use in dentistry (both primer and bonding resins) with antibacterial effect.

Advantages

• Compatible with a wide range of methacrylate materials;
• Dental uses guaranteeing a wide spectrum of employ;
• Antibacterial activity even at low concentrations;
• Maintenance of the mechanical properties of the final materials.