Monitoring periodontal disease status in smokers and nonsmokers using a gingival crevicular fluid matrix metalloproteinase-8-specific chair-side test

Background and Objective: With current periodontal diagnostic tools it is difficult to identify susceptible individuals or sites at risk. The aim of this study was to evaluate the efficacy of the matrix metalloproteinase (MMP)-8-specific chair-side dip-stick test in longitudinally monitoring the periodontal status of smoking (S) and nonsmoking (NS) patients with chronic periodontitis, using their gingival crevicular fluid (GCF) MMP-8 concentrations. Material and Methods: Clinical parameters, MMP-8 test results and concentrations were monitored in 16 patients after initial treatment and in 15 patients after scaling and root planing (SRP), every other month, over a 12-mo time period. Progressing and stable sites, and sites with exceptionally high MMP-8 concentrations, were analysed in smokers and nonsmokers. Results: SRP reduced the mean GCF MMP-8 levels, test scores, probing depth (PD), attachment loss (AL) and bleeding on probing (BOP). In sites of periodontal disease progression, the distribution of MMP-8 concentrations was broader than in stable sites, indicating a tendency for elevated concentrations in patients with periodontal disease. The mean MMP-8 concentrations in smokers were lower than in nonsmokers, but in smokers' and nonsmokers' sites with progressive disease, MMP-8 concentrations were similar. Sites with exceptionally elevated MMP-8 concentrations were clustered in smokers who also showed a poor response to SRP. In these sites, the MMP-8 concentration did not decrease with SRP and these sites were easily identified by the MMP-8 test. Conclusion: Persistently elevated GCF MMP-8 concentrations may indicate sites at risk, as well as patients with poor response to conventional periodontal treatment (e.g. SRP). MMP-8 testing may be useful as an adjunct to traditional periodontal diagnostic methods during the maintenance phase.