Comparison of gingival crevicular fluid sampling methods

Objective: Gingival crevicular fluid (GCF) is an important marker in diagnosis and therapy control of periodontitis. Different methods are used for collection, such as periopaper, paperpoints or washing. In this study we compared three different sampling techniques to identify the method with the highest output for bacterial load, cytokines, a host-derived enzyme and a bacterial protease.

Methods: 36 patients with severe chronic periodontitis were recruited. GCF samples were taken from four sites (each two sites one method). One week later the procedure was repeated with opposite sampling methods. Each 12 patients were put into one of the three groups (endodontic paperpoint (ep) – Periopaper (pp); ep-washing (wa); pp-wa). The parameters that had been determined were: loads of Aggegatibacter actinomycetemcomitans (A.a.) and Porphyromonas gingivalis (P.g.), levels of IL-6 and IL-8, activity of neutrophil elastase (HNE), level of RgpB (protease of P.g).

Results: A significantly higher load of both bacterial species was found by using ep and pp compared to wa. E.g., negative results for P.g. had been obtained for 21% of pp, 25% of ep and 44% for wa. The highest values for IL-8 were found by using wa (IL-8: wa 41.9 pg/site, ep 20.1 pg/site, pp 25.8/site). The level of IL-6 was higher in wa compared to ep. HNE activity was the highest in using ep. RgpB was detectable in suitable amounts only by the wa method, here 66% of the samples were positive (ep 52%, pp 51%). The level of RgpB correlated with the load of P.g.

Conclusion: In general the use of a paperpoint method (endodontic paperpoint and Periopaper, respectively) is suitable for determination of microbial and immunological parameters. Obtaining GCF by washing of the periodontal pocket seems to be necessary for special purposes such as determination of bacterial proteases, but cannot be recommended for analysing of microflora.