Saliva Biomarkers for Diagnosis of Periodontal Disease
May 09, 2015
Today’s dentist has several testing and diagnostic tools to assess the dental care needs of his patients. However, when it comes to periodontal disease testing, he is forced to rely on age old methods that only allow assessment of damage that has already occurred, such as visual examination, probing, radiography and so on.
Saliva consists of primarily water and a large number of constituents that have a role in maintaining oral health. These are enzymes, proteins, salivary ions, mucus as well as compounds that have antibacterial properties. It naturally follows that a study of these components or biomarkers can give vital information regarding various diseases affecting the oral cavity.
It can be a way of assessing who is more likely to develop periodontal disease as well as identifying patients already suffering from periodontal disease. Outward signs may not be visible yet or the disease may be in the inactive stage. It is also helpful in assessing sites of disease as well as monitoring progress of treatment.
Timely diagnosis means treatment can begin before any complications set in. However, not all of the patients are at equal risk as there are several factors that contribute to further deterioration. While some may proceed to advanced stages, others may not. Identifying people who are more susceptible helps to save costs in two ways. Firstly it prevents the use of costly aggressive treatment where not needed. Secondly it helps the dentist to plan timely intervention, prophylaxis and prevention of susceptible patients.
Saliva consists of secretions from specific salivary glands – parotid, sublingual, submandibular and minor salivary glands. In addition to this, there is GCF or gingival crevicular fluid, blood from any kind of wounds, burns or disease in the mouth and micro-organisms that include bacteria, virus and fungi.
Biomarkers Linked to Gum Diseases
Among the various biomarkers that have been studied and are considered to be indicative of periodontal disease are:
Secretory Immunoglobulin A (sIgA): Persons suffering from periodontal disease have higher levels of Ig A, Ig G and Ig M in the saliva. Moreover, the levels fall once it is treated
Lysozyme: Lysozyme is a salivary enzyme that prevents accumulation of plaque and therefore its low levels are indicative of higher risk.
Peroxidase: This is another salivary enzyme that has antibacterial properties as well as hampers formation of plaque.
Lactoferrin: A protein found in saliva which increases when there is gum disease.
Mucins: Mucins prevent adhesion of bacteria and their low levels can be a risk factor for periodontal disease.
Histatins: These with their antimicrobial qualities are essential for dental health and their low levels again can be indicative of higher possibility of gum diseases.
Matrix metalloproteinases (MMP) enzymes: Their presence indicates tissue inflammation and degradation. Out of these MMP-8, MMP-9 and MMP-13 point towards bone loss.
Acid Phosphatase (ACP) and Alkaline Phosphatase enzymes (ALP): ALP and ACP are present mainly in bones. Increase, particularly of ALP, indicates loss of alveolar bone which means periodontal disease is at the advanced stage.
Interleukin IL-1β: This is a pro-inflammatory cytokine which is known to worsen inflammation, thereby presence indicates worsening of disease.