Use of viral phage-therapy in periodontal disease: animminent future chance coming from the past

Agents that inhibit the synthesis of cell membrane (eg penicillin and cephalosporin); Agents that interfere with the cell membrane of the microorganism, influencing the permeability (for example some antimycotic agents); Agents that inhibit protein synthesis by influencing 30S or 50S sub-ribosomal units functions (e.g. tetracyclines, macrolides and clindamycin) Agents that block important metabolic phases of microorganisms (for example in sulfonamides). Agents that interfere with nucleic acid synthesis (eg. metronidazole and quinolones). Antimicrobial resistance can be classified into 3 groups: intrinsic, mutational and acquired resistance. Intrinsic resistance developed to a specific antibiotic is a peculiar natural feature of the microorganism. For example, some oral bacteria, such many streptococci, lack in nitroreductase needed for converting and processing metronidazole inactive metabolites in their active form and therefore are not affected by the drug. Mutational resistance occurs due to a spontaneous chromosomal mutation that produces a g en tically modiified bacterial popuplation that is resist ant to the drug. Finally, the acquired resistance is an acquisition from another microorganism of a genetic element that codes for antibiotic resistance. This process can take place by transduction, transformation or conjugation. Phages can play a key role in bacteria in oral dysbiosis even in the presence of resistant species. This previously ignored idea is becoming one of the most reliable hypotheses on the complex structures of oral biofilm. Bacteriophage therapy can be developed for most infections because bacteriophages are present in almost all species of bacteria. The oral cavity is one of the most densely populated habitats of microorganisms and includes about 6 billion bacteria.2–4 These bacteria together with saliva are the main components of oral microbioma, they can be harmful, but they also play beneficial and necessary role in the immune system. These bacteria have evolved to survive on the surface of the tooth, on the gingival epithelium and in the oral cavity. Bacteria aggregate into complex communities called biofilms. Within the oral biofilm the