Abstract
A broad spectrum of infections can occur in the oral cavity. These can be
classified according to the etiological agent in bacteria, viruses and fungi. The most
common bacterial infections are more putative in the hard tissues of the teeth, the pulp
organ and periodontal tissues. Fungal infections are caused by opportunistic fungi that
are generally present in the oral microbiota. In the oral and perioral regions, they are
mainly attributed to Candida albicans. As far as viral infections are concerned, the oral
and perioral cavity can be infected with numerous viruses, each capable of determining
a rather distinct clinical-pathological picture. Herpes viruses are the most common and,
in most cases, cause local disease in the short term. Human papillomaviruses are
responsible for clinically distinct, rosy-white, exophytic verruca-papillary lesions with
a typical surface alteration that gives a granular or cauliflower appearance.