Neutral proteases in crevicular fluid as an indicator for periodontal treatment intervention.

PURPOSE: To longitudinally determine if early therapeutic intervention, based on a positive neutral protease activity (NPA) assay score could effectively arrest the progress of periodontal disease destruction.

MATERIALS AND METHODS: 63 periodontal sites which had previously undergone probing attachment loss were identified from among 31 previously treated adult periodontitis patients who were monitored during periodontal maintenance for an average of 3 yrs. Clinical levels of gingival inflammation and attachment levels and NPA assay data were collected at the beginning of each maintenance visit. When a site tested negative with the assay, routine Supportive Periodontal Therapy (SPT) was followed during the same appointment, while sites exhibiting a positive NPA score received more aggressive periodontal treatment.

RESULTS: During the study period, 51 of 63 sites displayed at least one positive NPA score. Our protocol of administering periodontal treatment rendered at the visit showing a positive NPA score revealed that only 1 of the 51 sites lost > or = 1 mm attachment during the study period. The remaining 50 positive assay sites showed an overall gain of > or = 1 mm of probing attachment over the course of the study. 12 of 63 sites consistently tested negative for neutral protease enzyme activity and remained stable, although 9 of these sites exhibited bleeding on probing (BOP) at least once during this study. Initial group mean probing attachment measurements were 5.6 mm for NPA negative and 5.7 mm for NPA positive sites.