Biofilm formation on implants and prosthetic dental materials

The human body is subdivided into niches containing a wide variety of commensal microorganisms with essential functions for the host’s health. When the balance of the resident microflora changes, pathological conditions may occur. Based on this premise, this chapter first describes the composition of one of these niches, the oral cavity: its oral microbiome and the most frequent biofilm-related medical device infections promoted by multidrug-resistant strains, the so-called super bacteria or super bugs. In this context, the discussion focuses on the key events that unbalance the microbiome homeostasis and induce commensal bacteria to biofilm formation and describes how metabolites can influence the prevalence of bacterial species within the microbial community, thus promoting the onset of infectious diseases. As implantable devices are increasingly being used in dentistry, as in other medical fields, there is a pressing need for control strategies, able to counteract the events involved in biofilm formation, especially the adhesion phase, in order to reduce the occurrence of infection-associated implant failures. In this connection, the second part of this chapter briefly examines currently available strategies and the role of chemistry in biofilm prevention: the development of materials with intrinsic antibacterial properties, bioactive coatings with bactericide agents or materials delivering antibiotics, and nanostructured anti-adhesion surfaces or anti-biofilm bioactive molecules. Emerging and future approaches to fight biomaterial-associated infections are still to be clarified.