Microorganisms are the main causative agents for occurrence of endo-perio lesions. Complex anatomy of tooth system and growing resistant microbes to the available antimicrobial agents demands the development of new treatment strategies. The book presents how to biosynthesize, characterize and to determine the antibacterial efficacy of the silver nanoparticles (AgNPs) produced using fungi against the endo-perio pathogens P. gingivalis, B. pumilus, E. faecalis and to evaluate the cytotoxicity of AgNPs on normal human gingival fibroblasts (HGF) cell line.