Biofilm is a microbially derived community characterized by cells that are irreversibly attached to a substratum or interface or to each other, are embedded in a matrix of extracellular polysaccharides that they have produced and exhibit an altered phenotype with respect to growth rate and gene transcription. In 1890 Miller first observed microorganisms in association with pulp tissue and in 1987 first identification of biofilm structures in infected root canals was carried out by Nair. Since then it is explicit that bacteria are causative agent of endodontic infections. Bacteria can exert...