Smart dental materials for antimicrobial applications

Abstract

Smart biomaterials can sense and react to physiological or external environmental stimuli (e.g., mechanical, chemical, electrical, or magnetic signals). The last decades have seen exponential growth in the use and development of smart dental biomaterials for antimicrobial applications in dentistry. These biomaterial systems offer improved efficacy and controllable bio-functionalities to prevent infections and extend the longevity of dental devices. This review article presents the current state-of-the-art of design, evaluation, advantages, and limitations of bioactive and stimuli-responsive and autonomous dental materials for antimicrobial applications. First, the importance and classification of smart biomaterials are discussed. Second, the categories of bioresponsive antibacterial dental materials are systematically itemized based on different stimuli, including pH, enzymes, light, magnetic field, and vibrations. For each category, their antimicrobial mechanism, applications, and examples are discussed. Finally, we examined the limitations and obstacles required to develop clinically relevant applications of these appealing technologies.

Keywords: Antibacterial; Antibiofilm; Antifungal; Antimicrobial; Bioactive; Biofilm; Bioresponsive biomaterials; Restorative dentistry; Smart dental materials; Stimuli-responsive.

Graphical abstract

Fig. 1

Levels of smart biomaterials are classified as bioinert, bioactive, bioresponsive, or autonomous. Bioinert biomaterials cause minimal interaction with surrounding tissues and are the least smart. Bioactive materials release an active therapy after implantation to elicit a specific biological response at the material-tissue interface. Bioresponsive materials react to internal or external stimuli releasing specific agents for therapy. Finally, autonomous (or self-sufficient) materials respond holistically to the microenvironment complexity (adapting to changing conditions).

Fig. 2

Pathogen microorganisms associated to oral and systemic diseases.

Fig. 3

Configurations used as pH-responsive carriers for the delivery of oral antimicrobial therapies. After degradation/cleavage of the pH-sensitive bonds/compounds, the carriers release their payloads, which can be in the form of antimicrobial compounds, nano-fillers, or antimicrobial peptides.

Fig. 4

Schematic representation of the typical drug delivery mechanisms used by enzyme-responsive antimicrobial dental materials. The listed salivary and bacterial enzymes activate enzyme-responsive materials such as membranes, nanocarriers (liposomes, dendrimers), nano-hydrogels, or polymer composites to release antimicrobial therapies such as antimicrobial compounds, nano-fillers, or antimicrobial peptides.