An observational study in Periodontitis and Smoking, sponsored by Abant Izzet Baysal University. Recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-17.
Sponsored by Abant Izzet Baysal University · Observational
This observational study aims to examine the relationship between cigarette smoking and the levels of two proteins, mitofusin-1 (MFN1) and NLRP3, in the fluid found between the teeth and gums. These proteins are involved in processes related to cell function and inflammation.
Adults aged 25-65 years will be included in four groups: periodontally healthy nonsmokers, periodontally healthy smokers, nonsmokers with periodontitis, and smokers with periodontitis. Periodontitis is a gum disease that damages the tissues and bone supporting the teeth.
Participants will provide information about their health and smoking history and undergo a periodontal examination. Small samples of fluid from around the gums will be collected using paper strips before periodontal treatment. The samples will be analyzed for MFN1 and NLRP3.
Researchers will compare the amounts of these proteins across the four groups and examine their relationships with periodontal measurements and smoking history. No experimental medication or treatment will be assigned. Participants with periodontitis will be offered routine periodontal care after sample collection.
1,231 studies on the registry are indexed under Periodontitis; 295 are open to participants now.
This study's planned enrollment of 88 is close to the median of 90 across 372 observational studies indexed under Periodontitis.
Browse Periodontitis studies →Abant Izzet Baysal University is the lead sponsor of 250 studies on the registry; 59 are open to participants now.
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Adults aged 18-65 years attending the Department of Periodontology, Faculty of Dentistry, Bolu Abant Izzet Baysal University, Bolu, Türkiye, will be assessed for eligibility. Participants will have at least 20 natural teeth and either periodontal health on an intact periodontium or Stage III or Stage IV periodontitis. Four groups will be formed according to periodontal status and cigarette smoking history: periodontally healthy nonsmokers, periodontally healthy smokers, nonsmokers with periodontitis, and smokers with periodontitis.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
For the periodontitis groups: Stage III or Stage IV periodontitis according to the 2017 periodontal disease classification.
For the smoking groups: current cigarette smoking of at least 10 cigarettes per day for at least 5 years.
For the nonsmoking groups: fewer than 100 cigarettes smoked during the lifetime and no current use of tobacco or nicotine products.
Provision of written .
Exclusion Criteria:
Uncontrolled diabetes, immunodeficiency, or chronic inflammatory disease, or a serious systemic disease that may affect periodontal or mitochondrial responses.
Pregnancy or breastfeeding. Use of antibiotics, systemic , medications, or regular anti-inflammatory medications within the previous 3 months.
Periodontal treatment within the previous 6 months. Acute oral infection, periodontal abscess, or local pathology affecting the sampling sites.
Gingival crevicular fluid samples contaminated with blood or saliva, or insufficient for ELISA analysis.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adults aged 18-65 years with periodontal health on an intact periodontium, defined as probing depths ≤3 mm, full-mouth bleeding on probing \<10%, and no interdental clinical attachment loss or radiographic bone loss attributable to periodontitis. Participants will have smoked fewer than 100 cigarettes in their lifetime and will not currently use any tobacco or nicotine products. Periodontal measurements and gingival crevicular fluid sampling will be performed to assess MFN1 and NLRP3.
Adults aged 18-65 years with periodontal health on an intact periodontium, defined as probing depths ≤3 mm, full-mouth bleeding on probing \<10%, and no interdental clinical attachment loss or radiographic bone loss attributable to periodontitis. Participants will have smoked fewer than 100 cigarettes in their lifetime and will not currently use any tobacco or nicotine products. Periodontal measurements and gingival crevicular fluid sampling will be performed to assess MFN1 and NLRP3.
Adults aged 18-65 years with Stage III or Stage IV periodontitis according to the 2017 periodontal disease classification. Participants will have smoked fewer than 100 cigarettes in their lifetime and will not currently use any tobacco or nicotine products. Periodontal measurements and gingival crevicular fluid sampling will be performed before periodontal treatment to assess MFN1 and NLRP3. Routine periodontal treatment will be planned after sample collection.
Adults aged 18-65 years with Stage III or Stage IV periodontitis according to the 2017 periodontal disease classification. Participants will be current smokers who have regularly smoked at least 10 cigarettes per day for at least 5 years. Periodontal measurements and gingival crevicular fluid sampling will be performed before periodontal treatment to assess MFN1 and NLRP3. Routine periodontal treatment will be planned after sample collection.
Total Amount of MFN1 in Gingival Crevicular Fluid
The total amount of mitofusin-1 (MFN1) in pooled gingival crevicular fluid samples will be measured using a commercial enzyme-linked immunosorbent assay (ELISA). MFN1 amounts will be compared across the four groups defined by periodontal health or periodontitis and smoking status.
Time frame: Baseline, at the sample collection visit 24-72 hours after the periodontal examination and before periodontal treatment.
Total Amount of NLRP3 in Gingival Crevicular Fluid
The total amount of NLRP3 protein in pooled gingival crevicular fluid samples will be measured using a commercial enzyme-linked immunosorbent assay (ELISA). NLRP3 amounts will be compared across the four groups defined by periodontal health or periodontitis and smoking status.
Time frame: The total amount of NLRP3 protein in pooled gingival crevicular fluid samples will be measured using a commercial enzyme-linked immunosorbent assay (ELISA). NLRP3 amounts will be compared across the four groups defined by periodontal health or periodonti
Full-Mouth Mean Probing Depth
Probing depth will be measured in millimeters from the gingival margin to the base of the sulcus or periodontal pocket at six sites per tooth, excluding third molars. A full-mouth mean will be calculated for each participant. Values will be compared across the four study groups, and associations with gingival crevicular fluid MFN1 and NLRP3 amounts will be evaluated.
Time frame: Baseline, at the initial periodontal examination before gingival crevicular fluid sampling and periodontal treatment.
Full-Mouth Mean Clinical Attachment Level
Clinical attachment level will be measured in millimeters from the cementoenamel junction to the base of the sulcus or periodontal pocket at six sites per tooth, excluding third molars. A full-mouth mean will be calculated for each participant. Values will be compared across the four study groups, and associations with gingival crevicular fluid MFN1 and NLRP3 amounts will be evaluated.
Time frame: Baseline, at the initial periodontal examination before gingival crevicular fluid sampling and periodontal treatment.
Percentage of Sites With Bleeding on Probing
Bleeding on probing will be recorded at six sites per tooth, excluding third molars. The number of bleeding sites will be divided by the total number of examined sites and multiplied by 100 to calculate a full-mouth percentage for each participant. Scores range from 0% to 100%, with higher values indicating more widespread gingival bleeding. Values will be compared across the four study groups, and associations with gingival crevicular fluid MFN1 and NLRP3 amounts will be evaluated.
Time frame: Baseline, at the initial periodontal examination before gingival crevicular fluid sampling and periodontal treatment.
Full-Mouth Mean Plaque Index
Full-Mouth Mean Plaque Index
Time frame: Baseline, at the initial periodontal examination before gingival crevicular fluid sampling and periodontal treatment.
Full-Mouth Mean Gingival Index
Gingival inflammation will be assessed using the Löe and Silness Gingival Index at four surfaces per tooth, excluding third molars. Scores range from 0 to 3, with higher scores indicating more severe gingival inflammation. A full-mouth mean will be calculated for each participant. Values will be compared across the four study groups, and associations with gingival crevicular fluid MFN1 and NLRP3 amounts will be evaluated.
Time frame: Baseline, at the initial periodontal examination before gingival crevicular fluid sampling and periodontal treatment.
Plan to share: No
No publications or documents are linked to this record.
Started Aug 2026 (actual). Primary completion is estimated for Oct 2026, 2 months after the start.
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