Impact of emerging and re-emerging viral infections on periodontitis progression

Periodontitis is a chronic inflammatory disease that progressively destroys the tooth-supporting structures, including the gums, periodontal ligament, and alveolar bone. This destruction is primarily driven not by the bacteria themselves, but by the host's dysregulated immune response to a dysbiotic subgingival biofilm. Bacterial colonization in periodontal disease (PD) triggers both innate and adaptive immune responses. Furthermore, numerous viruses-including human cytomegalovirus (HCMV), Epstein-Barr virus (EBV), and herpes simplex virus (HSV)-have been linked to periodontal disorders and contribute to the etiopathogenesis of periodontitis alongside bacteria. Since its emergence in 2020, COVID-19 has posed a significant global health threat. SARS-CoV-2 infection within the periodontium may induce local inflammation, potentially exacerbating PDs. Given that viral replication and persistence in tissues are thought to increase with the severity of inflammation, the presence of these viruses may be linked to the development and progression of periodontitis. The current study is unique in its synthesis of data on a wide spectrum of viruses associated with periodontitis. This includes common viruses (EBV, HCMV, HSV, human papillomavirus (HPV), and human immunodeficiency virus (HIV)), emerging viruses (Chikungunya, Dengue), and novel viruses such as SARS-CoV-2. By providing a comprehensive overview of viral co-infections in periodontitis, this review advocates for the development of new antiviral diagnostic and therapeutic strategies that adopt a broad, virus-centric approach. We conducted a literature search across PubMed, Google Scholar, and Web of Science using keywords and Medical Subject Headings (MeSH) terms such as "viral infection," "periodontitis," and specific virus names.