Pathogenesis of Periodontal Disease in Individuals With Psoriasis

Specimens will be collected from four different teeth from each participant, each with the deepest pocket. Before collection, supragingival plaque will be gently removed with sterile curettes, the surfaces will be dried, and the tissue will be isolated with cotton rolls. Filter paper strips will be carefully inserted into the sulcus until slight resistance is felt, or no deeper than 1 mm to prevent mechanical trauma in patients with periodontitis. The strips will be left in the sulcus/pocket for 30 seconds. The GCF volume of each strip will be measured using a pre-calibrated electronic device (Peritron 8000). Four strips from each participant will be placed in coded sterile Eppendorf tubes and stored at -80°C until analysis.

Prior to saliva collection, participants will be instructed to abstain from caffeine and/or nicotine for at least 4 hours and alcohol for at least 24 hours. Participants will be asked to rinse their mouth with water and wait 5 minutes to prevent contamination. After waiting, they will be asked to collect saliva in the bottom of their mouth and then spit into a sterile metal cup for another 5 minutes. Unstimulated saliva samples will be transferred to sterile Eppendorf tubes. Saliva flow rate will be calculated by dividing the total saliva volume by the collection time for each participant. Samples will be stored at -80°C until the day of laboratory analysis.

Plaque Index (PI) (Silness and Löe, 1964) This index is used to evaluate the amount of dental plaque accumulation on tooth surfaces. Each tooth's four surfaces (buccal, lingual, mesial, distal) are examined using a probe or visually. Each surface is scored from 0 to 3. The average score is calculated for each tooth. The overall plaque index is obtained by averaging the scores from all examined teeth.

Score Description 0 No plaque.

• No visible plaque, but a slight film of plaque is detected when a probe is run along the gingival margin.
• Visible plaque along the gingival margin, forming a continuous band.
• Abundant plaque covering the gingival area and extending toward the middle of the tooth surface, including the interproximal spaces.

The Gingival Index is used to assess the presence and severity of gingival inflammation (gingivitis).

Four surfaces of each tooth (buccal, lingual, mesial, distal) are examined visually and with a periodontal probe. The evaluation considers color changes, edema (swelling), tissue consistency, and bleeding on probing. Each surface is scored from 0 to 3.

The average score per tooth is calculated, and then the overall average is used to determine the individual's GI score.

Score Description 0 Healthy gingiva: normal color and texture, no bleeding

• Mild inflammation: slight color change and swelling, no bleeding on probing
• Moderate inflammation: redness, edema, soft tissue, bleeding on probing
• Severe inflammation: marked redness and swelling, ulceration, possible spontaneous bleeding

This index is used to assess the presence and severity of gingival inflammation by observing bleeding after gentle pressure is applied to the gingival sulcus using a periodontal probe. A thin periodontal probe is gently inserted into the gingival sulcus with light pressure (approximately 20-25 grams). Bleeding occurring within 10-30 seconds is observed. Each measurement site is recorded as either "bleeding present" or "bleeding absent." Presence of bleeding is an early and sensitive indicator of gingival inflammation.

Score Description:

0 No bleeding

1 Bleeding present (mild or severe)

Using a Williams periodontal probe, the distance between the gingival margin and the base of the periodontal pocket is measured in millimeters at six sites per tooth: mesiobuccal, midbuccal, distobuccal, mesiolingual, midlingual, and distolingual. All teeth are measured. The values obtained from each site are summed and then divided by the total number of sites measured. This gives the average probing depth for the individual.

Measurement Interpretation 1-3 mm Healthy sulcus 4-5 mm Shallow to moderate pocket

≥6 mm Deep periodontal pocket (advanced disease)

Using a Williams periodontal probe, the distance between the enamel-cementum junction and the base of the periodontal pocket is measured in millimeters at six sites per tooth: mesiobuccal, midbuccal, distobuccal, mesiolingual, midlingual, and distolingual. All teeth are measured. The values obtained from each site are summed and then divided by the total number of sites measured. This gives the average probing depth for the individual.

CAL Value Interpretation 0-1 mm Healthy / minimal loss 2-3 mm Mild attachment loss 4-5 mm Moderate attachment loss

≥6 mm Severe attachment loss

This 16-item scale concerns how patients feel about their appearance. Each item is scored from 1 to 5 as follows: 1, strongly disagree; 2, somewhat disagree; 3, unsure; 4, somewhat agree; and 5, strongly agree. Scores range from 16 to 80, with higher scores representing greater social appearance anxiety.

Salivary cortisol, DHEA, and chromogranin A will be obtained from unstimulated whole saliva samples. Human salivary cortisol will be measured using a commercial enzyme-linked immunosorbent assay (ELISA) radioenzyme immunoassay kit according to the manufacturer's instructions. An ELISA kit will be used to measure DHEA, and the Human Chromogranin A ELISA Kit will be used to measure chromogranin A levels. Saliva samples will be kept on ice and stored at -20°C until analyzed. On the day of analysis, saliva samples will be centrifuged at 2000×g for 10 minutes to remove particulate material. All samples will be processed in triplicate during the same assay. Statistical analyses will be performed using the average of three replicate measurements.