Oral Biofluid Levels of Activin-A and Interleukin-1 Beta Levels in Periodontal Health and Disease

Participants were divided into three groups according to the diagnostic criteria proposed by the Classification of Periodontal and Peri-implant Diseases and Conditions; I. Periodontitis group (n=23), II. Gingivitis group (n=26) III. Periodontally healthy group (n=26)

Clinical periodontal indices included probing depth (PD), clinical attachment loss (CAL), the dichotomous scoring of bleeding on probing (BOP +/-), gingival index (GI), and plaque index (PI). Clinical recordings were performed at six points (mesiobuccal, buccal, distobuccal, mesiopalatal/mesiolingual, palatal/lingual, and distopalatal/distolingual) of all teeth, except the 3rd molars, by a single investigator using a conventional periodontal probe.

Interproximal radiographic bone loss on the digital panoramic radiographs were evaluated, as the ratio of the distance between the bone crest and the cemento-enamel junction to the length of the root.

GCF and unstimulated whole saliva samples were obtained 1 day following the clinical periodontal measurements. Immediately after saliva collection, GCF was collected from the buccal aspects of non-contiguous interproximal sites in two single-rooted teeth via steril paper strips. Fluid samples were obtained from two deepest pockets in periodontitis group and the most inflamed sites with clinical signs of redness or edema in gingivitis group. In the periodontally healthy groups, samples were taken from the sites without visible inflammation. All samples were stored at -80 °C until further analysis.

Measurement of Activin-A and IL-1β levels in GCF and saliva samples were performed by the commercially available enzyme-linked immunosorbent assay (ELISA) kits. While GCF cytokine levels were expressed as both total amounts at two samples per 30 s and concentrations, salivary cytokine levels were presented as concentrations.