Fluid sampling and examination
inflammation, Periodontitis, RA, attachment loss, trauma
INFLAMMATION, PLAQUE, PERIODONTITIS
Synovial fluid and serum samples were collected the same day of baseline clinical examination whereas the GCF samples were collected the day after to avoid the contamination of crevicular fluid with blood associated with the probing of inflamed sites. Patients of all study groups provided serum and GCF samples at baseline; only the RA patients agreed to provide synovial fluid samples. Periodontitis patients in our study who received SRP provided GCF samples 3 months after treatment.Synovial fluid sample collection was performed via arthrocentesis from inflamed knee joint. GCF samples were obtained from the buccal aspects of two interproximal sites in teeth that had the highest signs of inflammation and attachment loss. Selected site was first isolated with cotton rolls and air-dried and samples were collected after meticulous removal of supragingival plaque. For the periodontally healthy groups, samples were collected from the upper first molar. Filter paper strip (Periopaper; ProFlow Inc., Amityville, NY, USA) was placed in the selected sites for 30 s. Care was taken to avoid mechanical trauma and blood strips contaminated were discarded. For serum sample, 5 ml aliquot of blood was obtained. After collection, samples were immediately centrifuged and stored at − 80 °C until further use. Samples were assayed for PRL by using ELISA kits (Prechek Bio, Inc. CA, USA), according to manufacturer’s instructions using human recombinant standards. Results were expressed as concentrations in nanograms per milliliter (ng/ml); sensitivity of the kit was 5 ng/ml.