An introduction to antibacterial materials in composite restorations

The longevity of direct esthetic restorations is severely compromised because of, among other things, a loss of function that comes from their susceptibility to biofilm-mediated secondary caries, with Streptococcus mutans being the most prevalent associated pathogen. Strategies to combat biofilms range from dental compounds that can disrupt multispecies biofilms in the oral cavity to approaches that specifically target caries-causing bacteria such as S mutans. One strategy is to include those antibacterial compounds directly in the material so they can be available long-term in the oral cavity and localized at the margin of the restorations, in which many of the failures initiate. Many antibacterial compounds have already been proposed for use in dental materials, including but not limited to phenolic compounds, antimicrobial peptides, quaternary ammonium compounds, and nanoparticles. In general, the goal of incorporating them directly into the material is to increase their availability in the oral cavity past the fleeting effect they would otherwise have in mouth rinses. This review focuses specifically on natural compounds, of which polyphenols are the most abundant category. The authors examined attempts at using these either as pretreatment or incorporated directly into restorative material as a step toward fulfilling a long-recognized need for restorations that can combat or prevent secondary caries formation. Repeatedly restoring failed restorations comes with the loss of more tooth structure along with increasingly complex and costly dental procedures, which is detrimental to not only oral health but also systemic health.