New Biocidal Additive for Resin-Based Dental Composites: Is Modification with Didodecyldimethylammonium Bromide...

Area of Science:

• Materials Science
• Biomaterials Engineering
• Dental Materials

Background:

• Dental composites are susceptible to bacterial colonization and shrinkage stress, impacting longevity.
• Antimicrobial agents are needed to enhance the performance and durability of resin-based dental composites (RBCs).
• Didodecyldimethylammonium bromide (DDAB) is a quaternary ammonium compound with potential biocidal properties.

Purpose of the Study:

• To develop and characterize experimental resin-based dental composites (RBCs) incorporating didodecyldimethylammonium bromide (DDAB) as a biocide.
• To evaluate the effects of DDAB on the mechanical properties, physical characteristics, and antibacterial activity of RBCs.
• To assess the potential of DDAB-modified RBCs in reducing bacterial colonization and shrinkage stress.

Main Methods:

• Experimental RBCs were formulated with varying concentrations of DDAB (0-3 wt%).
• Mechanical properties (hardness, flexural strength, diametral tensile strength), physical properties (shrinkage stress, water sorption, solubility), and surface free energy were measured.
• Antibacterial activity was assessed using cytometric analysis against Streptococcus mutans, Escherichia coli, and Candida albicans.

Main Results:

• DDAB incorporation influenced mechanical properties, with some concentrations affecting hardness and flexural strength.
• Shrinkage stress was reduced with increasing DDAB concentration, while water sorption and solubility showed varied responses.
• RBCs with 3 wt% DDAB demonstrated significant reduction in viable Streptococcus mutans (71%), Escherichia coli (51%), and Candida albicans (24%) after 60 minutes.

Conclusions:

• Didodecyldimethylammonium bromide shows promise as an effective biocide in resin-based dental composites, reducing bacterial load and shrinkage stress.
• However, the concentration of DDAB must be carefully optimized to avoid negative impacts on mechanical properties like hardness and water sorption.
• Further investigations are required, including cytotoxicity, genotoxicity, ion release, and long-term aging behavior, to fully assess the clinical viability of DDAB-modified RBCs.