Periodontal Microbiome and Diagnosis

Chronic periodontitis is a chronic inflammatory disease associated with a polymicrobial biofilm that results in the destruction of periodontal tissues in susceptible individuals.  Objectives: We are entering an era of “Precision or Personalised Medicine” where large molecular data sets can be obtained for individual patients.  These data sets will allow individual patient risk-assessments for oral disease based on genomic, oral microbiomic and other analyses.  This information will allow patient and site-targeted preventive and/or therapeutic interventions that will be more cost effective and produce better outcomes for the patient.  Methods: Advances in the determination of the periodontal microbiome has led to a new paradigm of disease centred around the disruption of homeostasis (dysbiosis) by the emergence of a “keystone” pathogen or pathobiont in subgingival plaque that leads to disease initiation and progression.  One such keystone pathogen is Porphyromonas gingivalis that through its extracellular proteinases, that are released into the host’s tissues, dysregulate the immune response to cause tissue destruction and allow proliferation of the subgingival biofilm community.  Results: In prospective clinical trials the percentage levels of P. gingivalis in subgingival plaque have been shown to predict disease progression at that site.  This has resulted in the development of a chairside diagnostic for P. gingivalis that can rapidly and accurately determine the level of the organism in saliva and plaque samples with a sensitivity of 92% and specificity 96%.  Conclusion: Chairside diagnostics for patient and site-specific risk assessment are being developed to allow targeted and personalised preventive interventions.