In Vitro Evaluation of the Antimicrobial Properties of Natural Toothpastes Containing Silver, Citrus, and Cranberry Extracts Against Oral Pathogenic Microorganisms

Natural toothpastes were introduced to limit the use of chemical ingredients commonly found in conventional toothpastes. The purpose of this in vitro study was to evaluate the antimicrobial properties of three developed natural toothpastes containing different antimicrobial agents: (a) Biosecur Organic Oral Care (BOOC), (b) Microsilver BG, and (c) Cranberry LG. These toothpastes were compared with a natural toothpaste of the same composition but without any added natural antimicrobial agent (negative control), as well as with a commercial synthetic toothpaste (positive control). The antimicrobial properties of the toothpastes were assessed using the disc diffusion test against three oral pathogens: Candida albicans, Streptococcus mutans, and Prevotella intermedia. Each tested toothpaste sample was placed in Petri dishes, where specific microorganisms selected for the study were cultivated. After incubation, the circular area formed around the discs (diameter), known as the inhibition zone, was measured demonstrating the inhibitory effect of the product on the microorganisms used in the efficacy test. All the experimental toothpastes exhibited higher antimicrobial properties compared to the negative control group, except for Streptococcus mutans, where only BOOC-containing toothpaste presented significant higher inhibition zones (p < 0.001). Considering the outcomes of the antimicrobial property test, the most effective natural experimental toothpaste was the BOOC-containing one, which showed better antimicrobial behavior even from the commercially available synthetic toothpaste (positive control). The tested natural antimicrobial agents were effective for enhancing the antimicrobial properties of the experimental toothpastes that were included, especially Biosecur Organic Oral Care agent.