The Current Antimicrobial and Antibiofilm Activities of Synthetic/Herbal/Biomaterials in Dental Application

Abstract

Herbal and chemical products are used for oral care and biofilm treatment and also have been reported to be controversial in the massive trials conducted in this regard. The present review is aimed at evaluating the potential of relevant herbal and chemical products and comparing their outcomes to conventional oral care products and summarizing the current state of evidence of the antibiofilm properties of different products by evaluating studies from the past eleven years. Chlorhexidine gluconate (CHX), essential oils (EOs), and acetylpyridinium chloride were, respectively, the most commonly studied agents in the included studies. As confirmed by all systematic reviews, CHX and EO significantly control the plaque formation and gingival indices. Fluoride is another interesting reagent in oral care products that has shown promising results of oral health improvement, but the evidence quality needs to be refined. The synergy between natural plants and chemical products should be targeted in the future to accede to the formation of new, efficient, and healthy anticaries strategies. Moreover, to discover their biofilm-interfering or biofilm-inhibiting activities, effective clinical trials are needed. In this review article, therapeutic applications of herbal/chemical materials in oral biofilm infections are discussed in recent years (2010-2022).

Figure 1

QS mechanism in gram-categorized species. The canonical QS signaling and the Agr system are the most typical processes involved in the biofilm formation in gram+ bacteria S. aureus. This system includes four genes (AgrA-D) under the control of one operon. The products of this operon include virulence factors such as toxins and proteases. AgrD is converted to autoinducer peptides (AIPs) during secretion through AgrB to out of the cell where it activates the transmembrane AgrC by phosphorylation. The activated AgrC further activates AgrA that promotes the expression of targeted genes by influencing two promoters (P2 and P3). P2 regulates the Agr operon system, and P3 activates the expression of RNAIII which is the key regulator of different factors relating QS and biofilm formation. RNAIII upregulates virulence factors and inhibits factors contributing to bacterial dispersal. The balancing function Agr proteins on bacterial swarming and infection makes them promising targets for developing therapeutic antibiofilm agents [69].

Figure 2

QS mechanism in gram-categorized species. In gram− bacteria biofilm formation, QS signaling involve autoinducer acyl-homoserine lactones (AHLs) that help communication among bacteria and modulate targeted genes expression by activating corresponding cytoplasmic receptors. The Luxl/luxR transcriptional factors are other essential regulating factors activated by AHLs and control the expression of various virulence factors in different gram− bacteria such as pigments, carbohydrate-binding proteins, various proteases such as elastase, toxin, different autoinducers such as Pseudomonas quinolone signal (PQS), CAI-1, and AI-2, as well as QS receptors such as LasI/LasR, RhlI/RhlR, CqsS, and LuxPQ. Specific autoinducers can also further promote other adhesives and virulence factors [69].

Figure 3

The four main stages of biofilm formation process in the oral cavity [25].

Figure 4

The synthesis of (a) linear polyethyleneimine and (b) branched polyethyleneimine [44].

Figure 5

Antibiofilm activities and mechanisms of herbal and neutral materials.

Figure 6

Different components of garlic [71].

Figure 7

Structure of important bioactive constituents present in garlic [71].

Figure 8

Antibacterial, antiviral, and antifungal activities of extract of garlic.