Role of Salivary Matrix Metalloproteinase-8 (MMP-8) in Chronic Periodontitis Diagnosis

Periodontitis is an inflammatory disease of the periodontium. Any imbalance between the matrix metalloproteinases (MMPs) secreted by neutrophils and tissue inhibitors initiates the destruction of collagen in gum tissue, leading to chronic periodontitis. This study aimed to correlate salivary levels of MMP-8 and periodontal parameters of chronic periodontitis to establish MMP-8 as a noninvasive marker for the early diagnosis of chronic periodontitis. The study involved 40 subjects visiting the periodontic OPD of Dr. Ziauddin Ahmad Dental College and Hospital, located in Aligarh, U.P., India, from 2011 to 2012. The subjects were divided into two groups: group I consisted of 20 periodontally healthy subjects (controls) while group II consisted of 20 patients with chronic periodontitis. Chronic periodontitis was assessed on the basis of several periodontal parameters, including pocket probing depth (PPD), clinical attachment level (CAL), gingival index (GI), and plaque index (PI). Around 3ml of unstimulated and whole expectorated saliva was collected for MMP-8 estimation by ELISA using Quantikine human total MMP-8 immunoassay kits. Data were analyzed using STATISTICA (Windows version 6) software. Salivary MMP-8 levels of groups I and II were 190.91 ± 143.89 ng/ml and 348.26 ± 202.1 ng/ml, respectively. The MMP-8 levels and periodontal status (PPD, CAL, GI, and PI) of groups I and II showed positive and significant correlations (for PPD, r = 0.63, P < 0.001; for CAL, r = 0.54, P < 0.001; for GI, r = 0.49, P < 0.001; and for PI, r = 0.63, P < 0.001). The results of this study demonstrate elevated concentrations of MMP-8 in individuals with chronic periodontitis.