Objectives: To determine the effect of scaling and root planing (SRP) on the interrelations of subgingival periodontopathogens and both interleukin-8 (IL-8) and granulocyte elastase activity in gingival crevicular fluid (GCF), and to assess their relations to the short-term treatment response in management of chronic periodontitis.
Material and methods: GCF and subgingival plaque were collected from 16 subjects with untreated chronic periodontitis at baseline and 4 weeks after SRP. IL-8 levels were determined by ELISA. Granulocyte elastase activity was analyzed with a specific substrate, pGluProVal-pNA, and the maximal rate of elastase activity (MR-EA) was calculated. 5 DNA-probes were used to detect the presence of A. actinomycetemcomitans (A. a.), B. forsythus (B.f.), P. gingivalis (P.g.), P. intermedia (P.i.), and T. denticola (T.d.), with a sensitivity = 103 cells/paper point.
Results: IL-8 and MR-EA levels in GCF decreased significantly after SRP (p < 0.001) with a corresponding reduction of total count of the species. Of the sites with probing depth (PD) >/= 5.0 mm and co-infection by B.f., P.g., P.i. & T.d. at baseline, the sites without persistent co-infection of these species after SRP exhibited a significant reduction of IL-8 levels (p < 0.02), MR-EA levels (p < 0.02) and PD (p < 0.01). No such change was found in the sites where such a co-infection persisted. Moreover, reduction of IL-8 levels in those pocket sites was accompanied by a concomitant reduction of MR-EA (p < 0.02) and PD (p < 0.01), while no significant change in MR-EA levels and PD was noted in those pocket sites that exhibited an increase of IL-8 levels after SRP. At baseline, the former group of sites showed significantly higher IL-8 levels than the latter group of sites (p < 0.02).
Conclusions: IL-8-related granulocyte elastase activity was related to the change in infection patterns of the target periodontopathogens following scaling and root planing. Varying initial IL-8 levels in GCF and a corresponding shifting change of granulocyte elastase activity in GCF may characterize the different short-term treatment responses.