Evaluation of antibacterial efficacy of biosynthesized silver nanoparticles derived from fungi against endo-perio pathogens Porphyromonas gingivalis, Bacillus pumilus , and Enterococcus faecalis .

Background: Even after rapid progress in contemporary dental practice, we encounter the failures due to endodontic, periodontal, or combined lesions. Complex anatomy of tooth and resistant microbes demands the development of new treatment strategies.

Aim: The aim of this study is to biosynthesize silver nanoparticles (AgNPs) using fungi and determine the antibacterial efficacy against Porphyromonas gingivalis , Bacillus pumilus , and Enterococcus faecalis .

Materials and Methods: Fungi isolated from healthy leaves of Withania somnifera were used to biosynthesize AgNPs. The biosynthesized AgNPs were characterized by different methods, and antibacterial efficacy was evaluated by agar well diffusion method measuring the zone of inhibition. Test microorganisms were divided as Group 1: B. pumilus 27142 (American Type Culture Collection [ATCC]), Group 2: E. faecalis 29212 (ATCC), and Group 3: P. gingivalis 33277 (ATCC). Agents used for antibacterial efficacy were grouped as: AgNPs: A (20 μl), B (40 μl), C (60 μl), D (80 μl), E (100 μl), F (0.2% chlorhexidine [CHX]), G (2% CHX), H (Ampicillin), and I (sterile distilled water).

Results: Characterization studies showed the color change from colorless to reddish brown color; ultraviolet spectrum showed peak at 420 nm, transmission electron microscope revealed the particles spherical in shape and 10-20 nm size. Fourier transform infrared spectroscopy analysis revealed the presence of functional groups. Data collected for antibacterial efficacy were analyzed using one-way ANOVA and post hoc Tukey's multiple shows no significant difference among three groups ( P < 0.0001). AgNPs were as effective as CHX and positive control ampicillin. No zones were seen for I (distilled water).

Conclusion: Biosynthesized AgNPs showed efficient antibacterial efficacy. Therefore, it creates a new horizon in the management of endodontic, periodontal, and combined lesions.