Microbiology of dental decay and periodontal disease: A review.

OBJECTIVE: Aim: This review attempts to examine the microbiology, pathogenesis and current therapeutic approaches of dental caries and periodontal diseases with a special focus on the role of polymicrobial biofilms, the host-microbe interaction and the major pathogenic species involved in disease progression. PATIENTS AND METHODS: Materials and Methods: A thorough literature review was performed using major scientific databases such as PubMed, Scopus, Web of Science and Google Scholar. Studies that were published between 2000 and 2025 were included. Relevant experimental, clinical and review articles that focused on the etiology, microbial composition, virulence mechanisms, host immune responses and therapeutic approaches of dental caries and periodontal disease were analyzed. CONCLUSION: Conclusions: The oral cavity harbors over 700-800 bacterial species, of which the primary cariogenic pathogen is Streptococcus mutans and Porphyromonas gingivalis has been implicated as a major cause of periodontal disease. Dental caries progression is mostly attributed to acid production and demineralization of enamel, whereas periodontal disease is a result of dysbiotic shift in the subgingival microbiome with destructive host inflammatory responses. The "red complex" (P. gingivalis, Treponema denticola and Tannerella forsythia) has a high degree of synergistic virulence in advanced periodontitis. Biofilm formation, production of extracellular polysaccharide (EPS) matrix, quorum sensing and immune components (neutrophils, macrophages and matrix metalloproteinases or MMPs) are all factors that contribute to disease formation. Prevention strategies include oral hygiene measures, fluoride exposure, dietary modification, and antimicrobial agents, whereas treatment measures include mechanical debridement, systemic antibiotics, antimicrobial peptides, probiotics, and photodynamic therapy. Dental caries and periodontal diseases are the result of complex interactions between polymicrobial biofilms and immune responses by the host. A better understanding of the microbial ecology, virulence pathways and host-pathogen interactions is crucial in the process of improving prevention and treatment. Advances in targeted antimicrobial therapies and innovative therapeutic approaches hold promise for enhancing global oral health outcomes.