The effect of subgingival controlled-release delivery of chlorhexidine chip on clinical parameters and matrix metalloproteinase-8 levels in gingival crevicular fluid

Background: The present study evaluated the efficacy of controlled-release delivery of chlorhexidine gluconate (CHX) on clinical parameters and on gingival crevicular fluid (GCF) matrix metalloproteinase (MMP)-8 levels in chronic periodontitis patients. Methods: Twenty patients with chronic periodontitis were screened for 6 months. Two interproximal sites were selected from mesial surfaces of anterior teeth with probing depths of 6 to 8 mm that bled on probing in each patient. There were at least 2 teeth between the selected sites. CHX chip was inserted into a randomly selected site following scaling and root planing (SRP+CHX), while the other selected site received only SRP in each patient. Probing depth (PD), clinical attachment level (CAL), plaque index (PI), and papilla bleeding index (PBI) were recorded at baseline and at 1, 3, and 6 months. GCF MMP-8 levels were analyzed at baseline; 2 and 10 days; and at 1, 3, and 6 months by immunofluorometric assay (IFMA). Results: At baseline, there were no statistically significant differences in the mean PD, CAL, PBI, and PI scores between SRP+CHX and SRP alone groups. At 1, 3, and 6 months, all clinical parameters in each group significantly decreased (P <0.0167) when compared to baseline. The reduction of PD and improvement in CAL were higher in the SRP+CHX group compared to SRP alone at 3 and 6 months. However, the differences between the 2 groups were not statistically significant. PBI and Pi scores were not significantly different between SRP+CHX and SRP alone groups at any visit. GCF MMP-8 levels were similar in both groups at baseline. Intragroup analysis showed significant decreases in the GCF MMP-8 level for the SRP+CHX group between baseline and 1, 3, and 6 months (P <0.01). Intergroup analysis demonstrated significantly lower mean levels of GCF MMP-8 at 1 month in the SRP+CHX group compared to the SRP alone group (P <0.05). Conclusions: These data suggest that CHX chip application following SRP is beneficial in improving periodontal parameters and reducing GCF MMP-8 levels for 6 months' duration, The use of a chairside MMP-8 dipstick periodontitis test might be a useful adjunctive diagnostic tool when monitoring the course of CHX chip treatment.