Gingival Crevicular Fluid Levels of Apoptotic Regulatory Proteins Bax and Bcl-xl in Stage III Periodontitis

According to the 2017 World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions, participants were categorized into three groups:

I. Periodontitis group (n=23), II. Gingivitis group (n=26) III. Periodontally healthy group (n=26)

Clinical periodontal measurements included probing depth (PD), clinical attachment loss (CAL), the dichotomous scoring of bleeding on probing (BOP +/-), gingival index (GI), and plaque index (PI). All clinical parameters were recorded at six points (mesiobuccal, buccal, distobuccal, mesiopalatal/mesiolingual, palatal/lingual, and distopalatal/distolingual) per tooth, except the 3rd molars, by a single investigator (C.Ö.) using a manual periodontal probe.

The percentage of radiographic bone loss (RBL) at the interproximal sites were calculated on the digital panoramic radiographs as the ratio of the distance between bone level and the cemento-enamel junction to the length of the root.

GCF samples were obtained 1 day following the clinical periodontal measurements. 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.