Longitudinal evaluation of elastase as a marker for the progression of periodontitis.

To determine whether elastase levels in gingival crevicular fluid (GCF) could serve as a marker for the progression of periodontitis, we monitored GCF elastase and periodontal status in selected sites in 32 periodontally healthy volunteers and 31 periodontitis patients at intervals over a 6-month period. Clinical measurements included plaque index, gingival index, bleeding on probing, suppuration, probing depth, clinical attachment level, and relative attachment level measured with an automated disk probe. GCF elastase, detected by reaction with a fluorescent substrate, was assessed visually against fluorescence standards and quantitatively with a fluorometer. Bone loss was detected by subtraction radiography of standardized vertical bite-wing radiographs at baseline and 6 months. Mean visual elastase scores (VES) and quantitative elastase measurements were significantly higher (P < 0.001) in sites from periodontitis patients than in sites from healthy volunteers. When bone loss was used as the criterion for disease progression, significantly higher (P < 0.001) visual and quantitative GCF elastase levels were found at progressing sites than in nonprogressing sites in the periodontitis patients. The odds ratios (OR) for the event of developing bone loss with positive 4-minute and 8-minute VES tests were 4.2 (P < 0.001) and 7.4 (P < 0.001), respectively. When corrected for the tendency of progressing sites to be clustered within a subpopulation of patients, the OR for developing bone loss with the 4-minute and 8-minute VES tests were 3.1 (P < 0.007) and 4.9 (P < 0.001), respectively. These data indicate that sites with high levels of elastase are at significantly greater risk for progressive bone loss as assessed by digital subtraction radiography.